418 



MANIPULATION. 



perhaps, on the whole, the most satisfactory. Remarkable 

 examples of adaptation of structure to particular purposes 

 wiU be found in the insects named in the following list: — 



Hairs of Insects, 8fc. — These may be mounted either in fluid 

 or in the dry way ; in some spiders the hairs are branched, 

 in the larvae of many insects they are covered with spines, and 

 in the Crustacea they are provided either with spines, or are 

 plumed very like a feather; some of the most interesting 

 specimens of the latter kind wiU be found upon the body and 

 legs of all the crab tribe, but upon the flabeUa or sweeping 

 organs, which are situated within the branchial chamber, the 

 hairs present the greatest number of peculiarities ; they are 

 mostly scimetar shaped, and provided with teeth-like pro- 

 jections from the convex side, for the purpose of separating 

 the laminae of the branchias one from the other, in order to 

 admit water between them.* The remarkable structure 

 exhibited in the minute hairs of the larva of the Dermestes is 

 shown at C, figs. 1, 2, 3, ia plate 6 ; ia the early days of achro- 

 matic microscopes it was considered as a " test object," and 

 on this account has been retained and accurately represented. 

 The most interesting specimens are mentioned in the sub- 

 joined list : — 



Dermestes larva. Lobster, flabeUa, 



Diamond-beetle, leg, tail. 



Gnat, wing. Sea-mouse, 

 Hercules-beetle, Shrimp, 

 Larva, Tiger-moth, Spider, 

 Tussock-moth, Stag-beetle. 



Parts about the Mouth of Insects, 8fc. — Some of these, such 

 as the jaws of beetles and spiders, and the probosces of the 



* Vide a, paper by the author, " On the Structure and Use of the 

 FlabeUa," in vol. ii. of the Transactions of the Microscopical Society. 



Acilius sulcatus. 



Bee, 



Crab, claws, 



flabeUa, 



(small edible), 



flabeUa, 



