■jr4£ ANIMALCULA OF INFUSIONS, Jl 



ifolatfon in glafTes, I came to have the thirteenth 

 generation in fucceflion. , 



Here I mufl be allowed to make a digreflion. 

 One of the ftrongeft objections to the theory of 

 germs, is the great difficulty of conceiving the 

 fucceffive envelopement of animals in animals, 

 and plants in plants. It has been attempted to 

 obviate this objection, by dating, that it is more 

 adapted to ftartle the imagination than to confound 

 reafon, which admits of the infinite divifibility of 

 matter, and examples favourable to envelope- 

 ment have been adduced to weaken it. One egg 

 has oftener than once been found within another; 

 and fome ofTeous parts of one foetus included in 

 another foetus ( i ). The butterfly is firfl includ- 

 ed in the ihell of the chryfalis, and the chryfalis 

 in the (kin of the caterpillar. In vegetable feeds 

 are found the rudiments of the future plant; and 

 the fourth generation has been feen in a hyacinth 

 root (2). The volvox affords a new and beau-- 

 tiful inflance of envelopement; the eye has been 

 able to fee .the thirteenth generation: probably 

 that is not the lafl. I cannot fpeak otherwife, fmce 

 nothing but time was wanting to inveftigate whe- 

 ther further developement would appear. But 

 the naturalift is invited to extend this mofl im- 

 portant obfervation. 



Baker, 



(i) Hiftoire de L'Acad. Roy. 1742, 1746. 

 (2) Bonnet, Corps Organifes, torn, i- 



