COMPENDIUM. 285 



ments of its complete organization. I shall not embarrass the philosophic- 

 reader with a discussion of the reasons why it may be so. He will dis- 

 cover them by his own philosophical reflections. 



A learned author, Dr Martin Barry, maintains the unity of the ori- 

 ginal germ, as universally present, whereby there is a general correspon- 

 dence among those of all animals. No doubt, the elements of the parts 

 may be of similar description and qualities, yet under such differences as 

 shall, in maturity, determine the distinction of tribes. 



(1 .) Germ, Ortnn, Embryo. — Very indistinct ideas must be entertained 

 of the germ : it cannot be otherwise, when reasoning from conjecture only. 

 Whether solid or vascular, we may assume that it is long invisible, that it 

 is dormant, its existence maintained in passive life, and that its form is 

 afterwards demonstrated, in a certain state of evolution, by active life. 



In the course of that evolution, the matter of the ovum is formed as 

 an auxiliary to the germ, now known as the germinal vesicle. Vigour 

 and nutrition reciprocally promote the progress of the component parts. 

 The whole elements reside in the ovum, which becomes a sensible object, 

 undergoing a continual change, by an embryo beginning to occupy a por- 

 tion of it. 



Next, the irregular mass of vague and indistinct organization is rudely 

 moulded, as the foetus, composed of disproportioned and misshapen en- 

 larging parts. These are refined in more advanced stages, and at length 

 the young animal, which shall ultimately resemble the parent, is ushered 

 into life. 



The germ is thus an organism originally of unknown aspect, but 

 which, by successive nutrition and evolution of what must be the rudi- 

 ments of the future animal, is subsequently presented to view in a more 

 advanced irregular, and at length in a perfect form. 



Instead of an elementary germ, according to the preceding hypothesis, 

 should there be such a secretion and depositation of matter, from an indi- 

 vidual parent, and lodged in a peculiar cell, probably an analogous process 

 ensues. After passing through different advancing phases, the offspring 

 at last comes to light in whatever shape belongs to its nature. 



It is with the ovum of animals that we are most familiar ; for this is 



