SECT. XXXIX. i. i. GENERATION. 377 



parent ; and therefore in drift language it cannot be faid to be 

 entirely new at the time of its production ; and therefore it may 

 retain fome of the habits of the parent-fyftem. 



At the earlieft period of its exiftence the embryon, as fecreted 

 from the blood of the male, would feem to confift of a living 

 filament, with certain capabilities of irritation, fenfation, voli- 

 tion, and aflbciation ; and alfo with fome acquired habits or pro- 

 penfities peculiar to the parent : the former of thefe are in 

 common with other animals , the latter feem to diflinguifh or 

 produce the kind of animal, whether man or quadruped, with 

 the fimilarity of feature or form to the parent. It is difficult to 

 be conceived, that a living entity can be feparated or produced 

 from the blood by the action of a gland ; and which (hall after- 

 wards become an animal fimilar to that in whofe veflels it is 

 formed ; even though we fhould fuppofe with fome modern 

 theorifts, that the blood is alive ; yet every other hypothefis con- 

 cerning generation reds on principles (till more difficult to our 

 comprehenfion. 



At the time of procreation this fpeck of entity is received in- 

 to an appropriated nidus, in which it muft acquire twocircum- 

 ftances neceflary to its life and growth ; one of thefe is food or 

 fuftenance, which is to be received by the abforbent mouths of 

 its veffels ; and the other is that part of atmofpherical air, or of 

 water, which by the new chemiftry is termed oxygene, and 

 which affedts the blood by paffing through the coats of the vef- 

 fels which contain it. The fluid furrounding the embryon in its 

 new habitation, which is called liquor amnii, fupplies it with 

 nourifhment ; and as fome air cannot but be introduced into the 

 uterus along with a new embryon, it would feem that this fame 

 fluid would for a fhort time, fuppofe for a few hours, fupply 

 likewife a fufficient quantity of the oxygene for its immediate 

 exiftence. 



On this account the vegetable impregnation of aquatic plants 

 is performed in the air ; and it is probable that the honey -cup 

 or netary of vegetables requires to be open to the air, that the 

 anthers and fligmas of the flower may have food of a more 

 oxygenated kind than the common vegetable fap-juice. 



On the introduction of this primordium of entity into the 

 uterus the irritation of the liquor amnii, which furrounds it, 

 excites the abforbent mouths of the new veflels into adtion ; they 

 drink up a part of it, and a pleafurable fenfitf ion accompanies 

 this new action ; at the fame time the chemical affinity of the 

 oxygene afts through the veflels of the rubefcent blood - 9 arid a 

 previous want, or difagreeable fenfation, is relieved by this 

 procefs. 



VOL. I- A A a As 



