6l4 PHILOSOPHICAL TRANSACTIONS. [aNNO 1748. 



He annexed a figure of his wheat-island and its productions, all which will be 

 sufficiently intelligible without any more words ; and he reserved a multitude of 

 other observations he had by him in his journals, on infusions and other vege- 

 tating islands, for the Essay, which he hoped to publish in some months, if these 

 few thoughts and discoveries shall meet with approbation. See fig. 7- 



Then follow some observations on the generation of the paste-eel. The r.s. 

 knows it to be viviparous ; consequently perfect in this state, and such as may 

 continue to generate in the common way, as long as it has an element and matter 

 proper for its subsistence, yet is its own original generation, as far as he could 

 learn by observation, as that of all these microscopical animalcules, from a duc- 

 tile vegetating matter, the produce of wheat-flour and water ; though it under- 

 goes more changes than others, and lives in other conditions; ascending for 

 some time -before it enters its chrysalidal or egg-like state, whence it comes forth 

 a perfect eel. He had added a figure of a group of these eel-chrysalids, but the 

 detail of their metamorphosis he reserved for his little Essay, and not trouble the 

 S. now with an account too circumstantiated of every observation he had made on 

 them : besides that he was not yet thoroughly satisfied in the whole manner and 

 process of their generation. See fig. 8. 



He concludes with summing up his system in a few words : he supposes all 

 semen of any kind to be an exalted portion of animal or vegetable matter, se- 

 creted from the aliment of every generating subject, when it is adult, and no 

 further demand is made for its increase and growth ; this he supposes to be en- 

 dued with a proportionable vegetative force ; to be various in various circum- 

 stances, and heterogeneous in diflferent subjects ; but to be uniform in its produc- 

 tions, when it falls into a proper matrix, where it finds matter to assimilate, of 

 a quality and in a quantity sufficient to form that specific being ; while in other 

 circumstances, it will, if it extravasates, by the same vegetating force, vield all 

 the several phenomena above noticed. And thus he supposes he has obtained 

 what he first intended to make out, that the spermatic animals are not the effi- 

 cient cause of generation, but only a necessary consequence of principles in the 

 semen, which principles are necessary to generation. 



Thus had he connected his system with our countryman Dr. Harvey's obser- 

 vation of that fine tissue, or web-like expansion, observed in the uterus of does, 

 in the centre of which the embryo fetus, invested with its amnion and chorion, 

 was found to be lodged : for let the vegetation begin from the semen, and con- 

 tinue to assimilate the effluent matter from the matrix in which it has taken root, 

 and the fawn must come forth like any other specific animal or plant. 



He only further observes, that Lewenhoeck had discovered this vegetating 

 power in the semen, and had, like M. de Buffijn and him (Mr. N.) seen the fila- 

 ments from whence the spermatic animals spring ; he even calls them nerves and 



