ON GENERATION. 175 



I return to the ovary and the upper portion of the fowl's 

 uterus, in which the rudiments of the eggs are produced. These, 

 according to Aristotle/ in the first instance are small, and of a 

 white colour; growing larger, they subsequently become of a 

 paler and then of a deeper yellow. 



The superior uterus of Fabricius, however, has no existence 

 until after the hen has conceived, and contains the rudiments 

 of ova within it ; when it may be designated as a cluster of 

 papulae. And he therefore observes very properly, " The supe- 

 rior uterus is nothing more than an almost infinite congeries of 

 yelks, which appear collected as it were into a single cluster, of 

 a rounded form, and of every size, from that of a grain of mus- 

 tard to that almost of a walnut or medlar. This multitude of 

 vitelli is aggregated and conjoined very much in the manner of a 

 bunch of grapes, for which reason I shall constantly speak of it 

 as the vitellarium or raceme of yelks; a comparison which 

 Aristotle himself made in speaking of the soft or scaleless fishes, 

 when he says, 2 their ovary or roe is extruded agglutinated into 

 a kind of raceme or bunch of grapes. And in the same way 

 as in a bunch of grapes the several berries are seen to be of 

 different sizes, some large, some small, some of very diminutive 

 proportions, each hanging by its several peduncle, so do we find 

 precisely the same thing in the vitellarium of the fowl." 



In fishes, frogs, Crustacea, and testacea, however, matters are 

 otherwise arranged. The ovary or vitellary here contains ova 

 of one uniform size only, which being extruded increase, attain 

 maturity, and give birth to fetuses simultaneously. But in 

 the ovary of the common fowl, and almost all the rest of the 

 oviparous tribes, the yelks are found in various stages of their 

 growth, from dimensions that are scarcely visible up to the 

 full size. Nevertheless the eggs of the fowl and other birds, 

 (not otherwise than in those cases where the eggs are all engen- 

 dered and laid at the same moment,) ripen their foetuses under 

 the influence of incubation in the same nest, and produce them 

 perfect, nearly at the same time. In the family of the pigeons, 

 however, (which lay and incubate no more than two eggs in the 

 same nest,) I have observed that all the ova crowded together 

 in the ovary, with the exception of a single pair, were of the same 



1 Hist. Animal, lib. vi, cap. 2. 2 De Gen. Anim. lib. iii, c. 8. 



