Page:Popular Science Monthly Volume 30.djvu/430

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Johns Hopkins University Studies from the Biological Laboratory. Edited by Professors Newell Martin and W. K. Brooks. Vol. III. Baltimore, Md.: N. Murray, publisher.

When a former volume of this publication was reviewed in these pages, we commended the intelligence and liberality of the trustees for recognizing the importance of supporting a scientific publication of so special a character as this one. It is an encouraging omen for science in this country, that universities are recognizing the importance of publishing the results of their laboratory-work. Aside from the honor which an institution derives from an issue of this nature, there is good reason to believe that such a publication is a proper investment for a library fund. Every college library needs upon its shelves the journals and transactions of home and foreign societies. Instead, then, of subscribing for many of these, it were better to invest the same amount in a publication which, by judicious exchange, accomplishes the same result, with the added satisfaction of contributing its scientific work to the world. The numbers before us maintain the high standard of the previous volumes. Space will permit hardly more than a mention by title. The volume commences with a memoir entitled "Significance of the Larval Skin of Decapods," by H. W. Conn. The author states that Crustacea are a particularly favorable group for the study of phylogeny, and then proceeds to show the significance of the larval skin, and a very interesting discussion is given as to the ancestral form of Crustacea. From his study of the larval cuticle in the long- and short-tailed decapods, the author infers that "all decapods are to be referred back to a form similar to the protozoœ (zoea), in which the segments of the thorax and probably of the abdomen were present, and whose antennae were locomotive organs." Mr. Conn has another paper on the "Life History of Thalassema," a peculiar worm which lives within the empty shell of mellita or "sand dollar." He finds, among other interesting conditions, "the origin of the ova and spermatozoa as modified peritoneal cells, their growth in the body cavity, and their preservation in a sexually mature condition in sexual pouches. A segmentation of the embryo which is exceptionally among annelids perfectly regular, and the origin of the ventral nerve-cord from the ectoderm as a bilateral structure." Henry Leslie Osborn gives the results of his studies on the gill in some forms of prosobranchiate mollusca. Professor Lankester, in his valuable paper on mollusca, in the last edition of the "Encyclopædia Britannica," states his belief that the primitive gill of the mollusca was a ctenidium, a stalk with plates very much like the gill of Chiton and Fissurella. Mr. Osborn is led, however, from his embryological studies, to question this view, and to doubt whether the ctenidium form represents the primitive form of molluscan gill, and shows that in the ctenobranchs the gill is not a ctenidium, but a very much simpler organ. Its form compares closely with the primitive lamellibranchiate gill.

"Notes on the Composition of the Blood and Lymph of the Slider Terrapin," and also "On the Origin of the Fibrin formed in the Coagulation of Blood," by W. H. Howell. Both these memoirs are too technical for a short review.

"On the Action of Acid, Atropia, and Convallaria on the Heart; with some Observations on the Influence of Oxygenated and Non-Oxygenated Blood, and Blood in Various Degrees of Dilution," by H. G. Beyer, The title sufficiently indicates the scope of this paper, which will be more interesting to students of therapeutics, and to these and to physicians we commend it.

"The Action of Intermittent Pressure and of Defibrinated Blood upon the Blood-Vessels of the Frog and Terrapin," by Louis T. Stevens and Frederic S. Lee. This paper, like the last, is mentioned by title and for the same reason.

"Cranial Muscles of Amia calva, with a Consideration of the Relations of the Post-Occipital and Hypoglossal Nerves in the Various Vertebrate Groups," by J. Playfair McMurrieh. His investigations lead him to believe that the primitive Elasmobranchs, the Ganoids, and the Teleostei, to be connected along one line, and the Cyclostoma, Dipnoi, and Amphibia along another.

"On the Endings of the Motor Nerves in the Voluntary Muscles of the Frog," by Chr.