408 Co')*responde7ice of J, Nick/ks. 



true developing egg; and it \fould seem that in a few cases, at 

 least, it ma J develop either gemmately, or in true egg style, that 

 is, it may continue a germ-bud or become an egg, according as 

 it is or is not impregnated. 



But while this extension of the budding method of propaga- 

 tion subserves an end of vast importance among the inferior ani- 

 mals and in the plant kingdom, it cannot be properly an equiv- 

 alent to the normal sexual process. There is some great differ- 

 ence between what the female can bud out of herself, and what 

 the sexes combined produce. It is probable from facts which 

 have been observed both in plants and animals — though not yet 

 demonstrated — that bud propagation will in all cases, if followed 

 exclusively, end in the decline of the race, and its ultimate ex- 

 tinction; and that the sexes are required to keep up the sexual 

 system and thus to sustain the type at its normal level and secure 

 its perpetuity. This, if established as a real effect, is yet but a 

 partial or inadequate expression of the difference between the 

 two results. The subject opens a Avide field for exploration. 



One point seems clear, that the facts wdiich are coming to hght 

 are calculated largely to extend and define former views, not to 

 upset them. j. D. D. 



Akt. XXXIII. — Correspondence of M. Jerome NicUes^ dated 



Paris^ Jidy 2, 1857. 



Ohituarij, — Tlu'ee deaths of men of high importance in the scientific 

 world, Cauchy, Thenard and Colla, have taken place since our last commu- 

 nication, two of them, in particular, an irreparable loss to science. \Ve 

 mention at this time some details respecting Cauchy, reserving for a fu- 

 ture occasion our remarks on Thenard. M. Colla, director of the observ- 

 atory at Parma, died rather suddenly at the age of fifty -one vears, and 

 though less eminent than the two just mentioned, his decease has occa- 

 sioned no less regret. 



^ Augustin Cauchy was born in August, 1789, lie pursued his educa- 

 tion for a while in the Polytechnic School, and at eighteen years of age 

 left to enter the Department of Engineering. Soon after, he made 

 his first publications, commencing with a chef-d'oeuvre, a demonstration 

 of Euler's celebrated theorem on Polyhedrons, supplying thus what had 

 been wanting in geometry for 2000 years. Soon after, he gave a complete 

 deinonstration of one of the theorems left by Fermat to his successors, 

 which the best geometer had hitherto demonstrated only as regards some 

 particular cases. He brought out a beautiful theorem, on the number of 

 values which a function can have when we permute its letters in all possi- 

 ble ways. This theorem enabled Abel, twenty years later, to prove that 

 algebraic equations of the fifth and higher degrees could not he resolved. 

 Having been made a member of the Academy of Sciences in 1816, m 

 place of the great Carnot, whom Ae government of the Bourbons had sent 



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