190 GENERATION. 



On the contrary, when the body is cold, and when the penis is ex- 

 posed to cold, it does not swell to that size that it does in the other 

 case. 



In both these cases it is equally rigid, and is not capable of further 

 distention. It is well known that cold applied to the skin becomes a 

 stimulus to the muscles of the body, and of course to [those of] the 

 penis ; so that it is not capable of its full distention [under the influence 

 of cold]. 



Of the different Kinds of Female Parts of Generation, commonly 

 called ' Ovaria.' 



The first kind includes those where the ovaria exist in the unimpreg- 

 nated state 1 ; and the only difference between that state and the impreg- 

 nated one, is the increase of the size of some part of these ovaria. 

 Probably the only part which constitutes the ovum in the unimpreg- 

 nated state, is, in birds 2 , the part which forms the cicatricula in the in- 

 creased state, and that the increase is due to the addition of the yolk only. 

 The class called amphibia 3 , and the class of fishes called cartilaginous 4 , 

 also present this kind of ovaria. All that exemplify this kind have the 

 oviduct, which I believe adds to the egg a second part, viz. the al- 

 bumen, so that tbe eggs of such are, I believe, always composed of two 

 parts. 



The second kind includes those which have no ovaria in the unim- 

 pregnated state, and where there is a new creation every time they are 

 preparing or prepared for propagation, so that the whole body of 

 the ovarium is removed each time they do propagate. These have no 

 oviduct ; and it is probable from this circumstance that the ova are 

 only composed of one substance ; such I believe is the case with all the 

 pectinated gill-fish, or those which have roes 5 . 



The third kind would appear to be a mixture of both, partaking of 

 the first from their having oviducts ; and of the second, from their 

 having no ovaria in the unimpregnated state. The ova are, therefore, 

 entirely formed at the proper seasons, as in the second, but differ in 

 respect to situation ; for here they are formed in the oviducts them- 

 selves. The number of these ducts is increased in many, so as to allow 

 for the proper number of eggs, while in others there are only two ducts. 



1 [Or rather ' unexcited ' state ; the ovary of the bird acquires its full size without 

 any impregnation.] 



2 [Hunt Preps. Nos. 2726, 2730, 3380.] 



s [lb. Nos. 2695-2724.] [* lb. Nos. 2676-2694.] 



s [lb. Nos. 2680 (Eel), 2661, 2662 (Salmon), &c., 2663-2674.] 



