126 PHILOSOPHICAL TRANSACTIONS. [aNNO 1771. 



the warmth of the season. Nor is a single insect to be esteemed the whole pro- 

 duct of an egg, since it has been cleaely shown, that 10 generations succeed 

 each other; the first rudiments of which must have been originally in the egg, 

 as the females have no communication with the males but in autumn. The 

 wonder however becomes still greater, when we consider the number of indivi- 

 duals in each generation; this being, he is fully convinced, at a medium, not 

 less than 50. Whoever pleases to multiply by 50, 9 times over, may by this 

 means form some notion of the great number of insects produced from a single 

 egg; but will at the same time find that number so immense, as to exceed all 

 comprehension, and indeed to be little short of infinity. How far this can be 

 reconciled with any theory of generation which the ingenuity of man has hitherto 

 invented, may be a contemplation not altogether unworthy our curiosity, though 

 he fears it will not turn out much to the credit of our reasoning faculties. 



The ancient doctrine of equivocal generation, as also that from an admixtion 

 of the seminal matter of both sexes, being now quite rejected by all modern 

 naturalists; 2 other opinions seem to have sprung up in their stead. While one 

 party asserts that the original organization of the foetus exists in the ovary of 

 the female, and that it is vivified by a subtile spirit in the spermatic fluid of the 

 male; the other lays it down for a certainty, that the eggs of the female are 

 only to be considered as a proper nidus, provided for the reception of those mi- 

 nute animalcules, with which the male semen is found to abound. As the 

 former opinion does not appear to have any certain fact to support it, we may 

 well suspect an insufficiency in the cause to produce the effect assigned; but, 

 supposing it adequate to the production of one generation, who can conceive a 

 subtile spirit to remain in force for lO generations, and that through all the va- 

 rious seasons of the year? With regard to the latter, he must observe, that 

 the animalcules of Leuwenhoeck being compared with Malpighi's first rudi- 

 ments of the chick, their resemblance is not so striking as to afford the least 

 conviction : but should we allow these animalcules requisite to produce the first 

 generation, how then are the subsequent 9 generations produced without them ? 

 Not being able to answer these queries himself, nor expecting them to be readily 

 answered by others; it seems most prudent to observe with diligence what nature 

 does, without being over anxious to discover by what means. Let us rest satis- 

 fied in admiring the wonderful effects of generation, while we refer the primary 

 efficient cause to the eternal will and power of an Almighty Creator. 



XXIII. Meteorological Observations at Ludgvan in Mouni's-Bay, Cornwall, 

 1770. By William Borlase, D. D., F. R. S. Communicated by Dr. Jere- 

 miah Milks, Dean of Exeter, and F. R. S. p. 195. 



This is another register of the weather, 2 times in each month of the year 



