128 HISTORY OF CRUSTACEA. CHAP. XII. 



To review the developmental history of the different 

 Malacostraca in detail would furnish no results at 

 all correspondent to the time occupied by it, if our 

 knowledge was more complete it would be more profit- 

 able. I therefore abandon it, but will not omit to 

 mention that in it many difficulties which cannot at 

 present be satisfactorily solved would present them- 

 selves. To these isolated difficulties I ascribe the less 

 importance, however, because even a little while ago, 

 before the discovery of the Prawn-Nauplius, this entire 

 domain of the development of the Malacostraca was 

 almost inaccessible to Darwin's theory. 



Nor will I dwell upon the contradictions which appear 

 to result from the application of the Darwinian theory 

 to this department. I leave it to our opponents to 

 find them out. Most of them may easily be proved to 

 be only apparent. There are two of these objections, 

 however, which lie so much on the surface that they 

 can hardly escape being brought forward, and these, I 

 think, I must get rid of, 



" The peculiarities in which the Zoese of the Crabs, 

 the Porcellance, the Tatuira, the Hermit Crabs, and the 

 Prawns with Zoea-brood agree, and by which they are 

 in common distinguished from the larvae of Peneus 

 produced from Nauplii, forces us (it might be said) to 

 the supposition that the common ancestor of these 

 various Decapods quitted the egg in a similar Zoea- 

 form. But then neither Peneus with its Nauplius- 

 brood, nor even apparently the Palinuri could be re- 

 ferred back to this ancestor. The mode of development 



