42 



HISTORY OF CRUSTACEA. 



Chap. VI. 



with four (or five ?) fissures, which are not placed in 

 pairs but alternately to the right and left in successive 



( / segments. In other 

 \\^ animals of this order, 

 f which I have as yet 

 ,' ^ only cursorily examin- 

 ( ed, further differences 

 I will no doubt occur. 

 But why, in two orders 

 so nearly allied to each 

 other, should we find 

 in the one sach a con- 

 stancy, in the other 

 such a variability, of 

 the same highly im- 

 portant organ ? From 

 the schoolmen we need 

 expect no explanation, they will either decline the dis- 

 cussion of the " wherefore " as foreign to their province, 

 as lying beyond the boundaries of Natural History, or 

 seek to put down the importunate question by means of 

 a sounding paraphrase of the facts, abundantly sprinkled 

 with Greek words. As I have unfortunately forgotten 

 my Greek, the second way out of the difSculty is closed 

 to me ; but as I luckily reckon myself not amongst the 

 incorporated masters, but, to use Baron von Liebig's 

 expression, amongst the " promenaders on the outskirts 



5 Fig. 15. 



6 Fig. 16. 



Heart of a young Anilocra. 



Abdomen of the male of Entoniscus Cancrorum. 



h. Heart. 



I. Liver. 



