L ANIMALCULA OF INFUSIONS. 269 



' expand It without attacking its fubftances, I be- 



* lieve I may affirm that this body, immerfed in 

 ' the fluid, will refill the aftion of the fire. 



* I know well, that for eggs or germs to pre- 

 ^ ferve their fecundity, it is eflential not only that 



* the external integument remains entire, but that 

 f the interior retains the fame proportions and 

 ' the fame pliancy. Therefore we muft add to 

 ^ the preceding conditions, that no fluid is to be 

 ^ contained which heat can coagulate, and that 



^* the whole vefiels and fibres may be fufficiently 



* pliant to dilate without rupture, and, in con- 

 ■" trafting, to refume their original fituations. 



' Collecting and generalizing thefe ideas, I 

 ^ find that all the determinations are reduced, 

 *' firji^ To reciprocal indilfoiubility as well of the 

 ' contiguous parts of the exterior and interior 

 ^ parts of the germ, as of the medium in which 



* it exifts : Secondly^ To the fixed and refradlory 

 ' nature of the germ : Thirdly, To the propor- 



* tionate capacity of contradion and dilation of 

 ^ its whole parts. Germs continue fertile fo long 



* as the heat does not exceed the conditions with- 

 f- in which thefe determinations may fubfill ; and 

 ' they may do fo at heat far furpaffing that of 

 ^ boiling water. It is eafy to fee how the germ 



* may lofe them during its expanfion. 



' Explanations of this kind, I acknowledge, I 



* would prefer to thofe deduced from tranfparen- 



' cyj 



