II.] INCIPIENT STRUCTURES. 59 



known in a few of the two-winged flies. Now, how " Nat- 

 ural Selection," or any " laws of correlation," can account 

 for the gradual development of such an exceptional process 

 of development so extremely divergent from that of other 

 insects seems nothing less than inconceivable. Mr. Dar- 

 win himself " gives an account of a very peculiar and ab- 

 normal mode of development of a certain beetle, the sitaris, 

 as described by M. Fabre. This insect, instead of at first 

 appearing in its grub stage, and then, after a time, putting 

 on the adult form, is at first active and furnished with six 

 legs, two long antennae, and four eyes. Hatched in the 

 nests of bees, it at first attaches itself to one of the males, 

 and then crawls, when the opportunity offers, upon a female 

 bee. When the female bee lays her eggs, the young sitaris 

 springs upon them and devours them. Then, losing its 

 eyes, legs, and antennae, and becoming rudimentary, it 

 sinks into an ordinary grub-like form, and feeds on honey, 

 ultimately undergoing another transformation, reacquiring 

 its legs, etc., and emerging a perfect beetle ! That such a 

 process should have arisen by the accumulation of minute 

 accidental variations in structure and habit, appears to many 

 minds, quite competent to form an opinion on the subject, 

 absolutely incredible. 



It may be objected, perhaps, that these difficulties are 

 difficulties of ignorance that we cannot explain them be- 

 cause we do not know enough of the animals. But it is 

 here contended that this is not the case ; it is not that we 

 merely fail to see how " Natural Selection " acted, but that 

 there is a positive incompatibility between the cause as- 

 signed and the results. It will be stated shortly what won- 

 derful instances of coordination and of unexpected utility 

 Mr. Darwin has discovered in orchids. The discoveries are 

 not disputed or undervalued, but the explanation of their 

 origin is deemed thoroughly unsatisfactory utterly insuf- 

 23 " Origin of Species," 5th edit., p. 532. 



