central apse leads direct to the diaconicon, but never to the prothesis.
PROTISTA, a name invented by Ernst Haeckel (Generelle Morphologie der Organismen, 1866) to denote a group of organisms supposed to be intermediate between the animal and vegetable kingdoms. As knowledge advanced the precise limits of the group shifted, and Haeckel himself, in successive publications, placed different sets of organisms within it, at one time proposing to include all unicellular animals and plants, making it a third kingdom equivalent to the animal and vegetable kingdoms. Partly because the term represented an interpretation rather than an objective set of facts, the word Protista has not been generally accepted for use in classification, and, whilst recognizing that the limits of the animal and plant kingdoms are not sharply defined, modern systematists refrain from associating these doubtfully placed organisms simply because of the dubiety of their position. (See Protozoa.)
PROTOCOL (Fr. protocole, Late Lat. protocollum, from Gr. πρῶτος, first, and κολλᾶν, to glue, i.e. originally the first sheet of a papyrus roll), in diplomacy, the name given to a variety of written instruments. The protocollum was under the late Roman Empire a volume of leaves, bound together with glue, in which public acts were recorded, so as to guard against fraud or error on the part of those responsible for preparing them; and in later usage it came to be applied to the original drafts of such acts. Thus, too, the word prothocollare was devised for the process of drawing up public acts in authentic form (Du Cange, Glossarium lat. s.v. Protocollum). The use of the word protocollum for the introductory and other formulae in the medieval diploma (see Diplomatic) thus explains itself as implying a recorded usage in such matters.
In the language of modern diplomacy the name of “protocol” is given to the minutes (procès-verbaux) of the several sittings of a conference or congress; these, though signed by the plenipotentiaries present, have only the force of verbal engagements (see Congress). The name of “protocols” is also given to certain diplomatic instruments in which, without the form of a treaty or convention being adopted, are recorded the principles or the matters of detail on which an agreement has been reached, e.g. making special arrangements for carrying out the objects of previous treaties, defining these objects more clearly, interpreting the exact sense of a doubtful clause in a treaty (protocoles interpretatifs) and the like. Thus the famous Troppau protocol, which annunciated the right and duty of the European powers to intervene in the internal affairs of a state threatened with revolution, was from the point of view of its signatories merely a logical application of the principles contained in the treaty of the 20th of November 1815 (see Troppau). Occasionally also an agreement between two or more powers takes the form of a protocol, rather than a treaty, when the intention is to proclaim a community of views or aims without binding them to eventual common action in support of those views or aims; thus the settlement of the question of the Danish succession was recognized by the powers in conference at London, by the protocol of 1852 (see Schleswig-Holstein Question). Finally, “the protocol” (protocole diplomatique, protocole de chancellerie) is the body of ceremonial rules to be observed in all written or personal official intercourse between the heads of different states or their ministers. Thus the protocol lays down in great detail the styles and titles to be given to states, their heads, and their public ministers, and the honours to be paid to them; it also indicates the forms and customary courtesies to be observed in all international acts. “It is,” says M. Pradier-Fodéré, “the code of international politeness.”
See P. Pradier-Fodéré, Cours de droit diplomatique (Paris, 1899), ii. 499.
PROTOGENES, a Greek painter, born in Caunus, on the coast of Caria, but resident in Rhodes during the latter half of the 4th century B.C. He was celebrated for the minute and laborious finish which he bestowed on his pictures, both in drawing and in colour. Apelles, his great rival, standing astonished in presence of one of these works, could only console himself by saying that it was wanting in charm. On one picture, the “Ialysus,” he spent seven years; on another, the “Satyr,” he worked continuously during the siege of Rhodes by Demetrius Poliorcetes (305–304 B.C.) notwithstanding that the garden in which he painted was in the middle of the enemy's camp. Demetrius, unsolicited, took measures for his safety; more than that, when told that the “Ialysus” just mentioned was in a part of the town exposed to assault, Demetrius changed his plan of operations. Ialysus was a local hero, the founder of the town of the same name in the island of Rhodes, and probably he was represented as a huntsman. This picture was still in Rhodes in the time of Cicero, but was afterwards removed to Rome, where it perished in the burning of the Temple of Peace. The picture painted during the siege of Rhodes consisted of a satyr leaning idly against a pillar on which was a figure of a partridge, so life-like that ordinary spectators saw nothing but it. Enraged on this account, the painter wiped out the partridge. The “Satyr” must have been one of his last works. He would then be about seventy years of age, and had enjoyed for about twenty years a reputation next only to that of Apelles, his friend and benefactor. Both were finished colourists so far as the fresco painting of their day permitted, and both were laborious in the practice of drawing, doubtless with the view to obtaining bold effects of perspective as well as fineness of outline. It was an illustration of this practice when Apelles, finding in the house of Protogenes a large panel ready prepared for a picture, drew upon it with a brush a very fine line which he said would tell sufficiently who had called. Protogenes on his return home took a brush with a different colour and drew a still finer line along that of Apelles dividing it in two. Apelles called again; and, thus challenged, drew with a third colour another line within that of Protogenes, who then admitted himself surpassed. This panel was seen by Pliny (N.H. xxxv. 83) in Rome, where it was much admired, and where it perished by fire. In the gallery of the Propylaea at Athens was to be seen a panel by Protogenes. The subject consisted of two figures representing personifications of the coast of Attica, Paralus and Hammonias. For the council chamber at Athens he painted figures of the Thesmothetae, but in what form or character is not known. Probably these works were executed in Athens, and it may have been then that he met Aristotle, who recommended him to take for subjects the deeds of Alexander the Great. In his “Alexander and Pan” he may have followed that advice in the idealizing spirit to which he was accustomed. To this spirit must be traced also his “Cydippe” and “Tlepolemus,” legendary personages of Rhodes. Among his portraits are mentioned those of the mother of Aristotle, Philiscus the tragic poet, and King Antigonus. But Protogenes was also a sculptor to some extent, and made several bronze statues of athletes, armed figures, huntsmen and persons in the act of offering sacrifices.
PROTOGENES (E. Haeckel), a little-known genus of Foraminifera (q.v.), marine organisms, forming a naked flat disk with numerous long radiating pseudopodia: nucleus and contractile vacuole not seen, and reproduction unknown.
PROTOMYXA (E. Haeckel), a genus of Foraminifera (q.v.), marine organisms, of orange colour, naked and reproducing in a broad-cyst which liberates 1-flagellate zoospores.
PROTOPLASM, the name given in modern biology to a substance composing, wholly or in part, all living cells, tissues or organisms of any kind, and hence regarded as the primary living substance, the physical and material basis of life. The term “protoplasm,” from πρῶτος, first, and πλάσμα, formed substance, was coined by the botanist Hugo von Mohl, in 1846, for the “tough, slimy, granular, semi-fluid” constituent of plant cells, which he distinguished from the cell-wall, nucleus and cell-sap. This was not, however, the first recognition of the true living substance as such, since this step had been achieved in 1835 by the French naturalist F. Dujardin, who in his studies on Foraminifera had proposed the term “sarcode” for the living material of their bodies in the following words: “Je propose de nommer ainsi ce que d'autres observateurs ont appelé une gelée vivante, cette substance glutineuse,
