$U GENERATION. Sect. XXXIX. 2. 1. 



and fugar, whence arifes its white colour •, whereas the chyle or 

 fap-juice of vegetables, which exudes from wounds of birch or 

 maple-trees in the vernal months, is tranfparent, and confiftsoi.- 

 ly of fugar and mucilage, and in this circunallance diifers from 

 the chyle of animals. 



II. 1. The procefs of generation is ftill involved in impene- 

 trable obfcurity, conjectures may neverthelefs be formed con- 

 cerning fome of its circumilances. Firft, the eggs of fi(h and 

 frogs are impregnated, after they leave the body of the female ; 

 becaufe they are depofited in a fluid, and are not therefore 

 covered with a hard f hell. It is however remarkable, that neither 

 frogs nor fiih will part with their fpawn without the prefence 

 of the male ; on which account female carp and gold-fifh in 

 fmall ponds, where there are no males, frequently die from the 

 idiftention of their growing fpawn. 2. The eggs of fowls, 

 which are laid without being impregnated, are feen to contain 

 only the yolk and white, which are evidently the food or fuf- 

 tenance for the future chick. 3. As the cicatricula of thefe 

 eggs is given by the cock, and is evidently the rudiment of the 

 new animal j we may conclude, that the embryon is produced 

 by the male, and the proper food and nidus by the female. Foy 

 if the female be fuppofed to form an equal part of the embryon, 

 why fhould fhe form the whole of the apparatus for nutriment 

 and for oxygenation ? The male in many animals is larger, 

 ftronger, and digefls more food than the female, and therefore 

 fhould contribute as much or more towards the reproduction of 

 the fpecies ; but if he contributes only half the embryon and 

 none of the apparatus for fuftenance and oxygenation, the di- 

 vifion is unequal ; the ftrength of the male, and his confump- 

 tion of food are too great for the effect, compared with that of 

 the female, which is contrary to the ufual courfe of nature. 



It has been fuppofed by fome inquirers into the procefs of 

 generation, that the male femen in many animals could not come 

 into contact with the ovum of the female, and they have hence 

 fuppofed, that an aerial or ethereal emanation from the femen 

 virile might ferve the purpofe of flimulating into life the ovum 

 muliebre, becaufe in. the vegetable ftigma of fome flowers no 

 vcflels have been feen to receive and tranfmit the burfting an-» 

 ther-duft ; and becaufe it is not pofllble, that the ejaculatio 

 feminis in quadrupeds could fend it through the fallopian tubes 

 to the veficles of the ovaria. 



In refpect to the analogies from other animals, ift, It may 

 be obferved, that in the generation of frogs, it is well known, 

 that the male fperm is efTufed in contact with the female fpawn, 

 as it leaves her body, and that in flfh the male fperm is likewife 



efTufed 



