of these under the name of spermatic parts, say that the semen is formed from the ultimate nourishment, which with Aristotle they believe to be the blood, being produced by the virtue of the genital organs, and constituting the " matter" of the foetus. Now it is obvious enough that the egg is produced by the mother and her ultimate nutriment, the nutritious dew, to wit. That clear part of the egg, therefore, that primigenial, or rather antegenial colliquament, is more truly to be reputed the semen of the cock, although it is not projected in the act of intercourse, but is prepared before intercourse, or is gathered together after this, as happens in many animals, and as will perhaps be stated more at length by and by, because the geni- ture of the male, according to Aristotle, coagulates.
When I see, therefore, all the parts formed and increasing from this one moisture, as " matter," and from a primitive root, and the reasons already given combine in persuading us that this ought to be so, I can scarcely refrain from taunting and push- ing to extremity the followers of Empedocles and Hippocrates, who believed all similar bodies to be engendered as mixtures by association of the four contrary elements, and to become corrupted by their disjunction ; nor should I less spare Demo- critus and the Epicurean school that succeeded him, who com- pose all things of congregations of atoms of diverse figure. Because it was an error of theirs in former times, as it is a vulgar error at the present day, to believe that all similar bodies are engendered from diverse or heterogeneous matters. For on this footing, nothing even to the lynx's eye would be similar, one, the same, and continuous ; the unity would be ap- parent only, a kind of congeries or heap- a congregation or collection of extremely small bodies ; nor would generation dif- fer in any respect from a [mechanical] aggregation and arrange- ment of particles.
But neither in the production of animals, nor in the gene- ration of any other "similar" body (whether it were of animal parts, or of plants, stones, minerals, &c.), have I ever been able to observe any congregation of such a kind, or any divers mis- cibles pre-existing for union in the work of reproduction. For neither, in so far at least as I have had power to perceive, or as reason will carry me, have I ever been able to trace any " simi- lar" parts, such as membranes, flesh, fibres, cartilage, bone, &c.>
