19 



MSI--: -:f s- srnis 515!HSH 



r,,.,^'"' ^''I^'^f 'l^f 'tch has made similar experiments with similar results on Bcmhnir, 

 Cyclops, and C'anlhocampius, which he has not vet ntihlkJiPr] tLI u ''^"^/""f ' 



^ng as th.s IS possible they cannot be considered as diff",^tiating o Clian stcit 



htes^'sinc'l.'fn^'.^H'V^' proveninCrustacea will certainly be observed also with other Articu- 

 as in thT.. f , T P?''"'' '" P°^t-abdomen, there cannot occur the same differences 

 as in the case cited, but analogous ones will not be wanting. It is obvious that so caUed 



salt insects are the first ones which will need new and careful st dv TbnL t„ 

 l7o£T''' ^'P^'^' Hemipteraand Orthoptera, and Te spT'es r^ Sn nSH^re^atld 

 to other ones which do not live in salt regions Further it i« Pvi,]pn7tl,lt ^^.-f^ 

 changes will be the result of different conditi.^s of life So called "Sv^^^^^^^ 

 certainly nothing else and a vast field of observation anVs dy is op n^ ' b he re 

 markable discoveries of Mr. Schmaukevitch. I believe that we are now ju tified whe; 

 we exclude from generic characters all the following ones • juscinea when 



«m,li "".7 <^''''^''''^«^"" ba^ed on the number of parts, when the number ceases to be a 



mall one ; the more so when it varies in related species If a number klar-^er than .bout 

 appSr "Tn""" "k^ 'T '•" '=°°^^'^"^'>' °f ^^- -^"-ber in antennl'o nts and ana 



is nor^aleL'^cXJaXr "^"The''h.,V ^(' ^ 'f '''';^ '° ^''''' ''''^'' ^"^ ''^'' appendages, 

 and. can nnf hT.nn=, W ^' [ '' *"*'"' '"■"''''''' 'P'"«^' ^P^^r^' '^'-e often only sexua 



cnanging in the most related species and probably in the same species in Diptera. 

 3. T e presence or want of the ocelli or eyes is not a generic character.'^ 



principal hrnnrhLhf'"?^'',^''''' °"'^ '" "" '^"■''^''' ^^«S'"«<' generic characters, viz : the 

 principal branches, but certainly not after the bifurcation 



charaSrs"" '"'"''"'^ '"* ^""^ ^^ exclusion, it is important to state what is left for generic 



8houi?b!?used ] *"" ''^'''°'"^ '" '^' ''"^y °^ ^^"^"<' characters, I think the following 

 1. The form and relation of the three principal parts of the body, 

 o" ix '"'^''''"* providing nutrition (mouth J3art.s). 



locomotilm °''^'"' ""'''"^ ^'°'''^'' "'' ''"''^'"S of the mouth parts, /. e., the organs of 

 The anatomical characters may be of prominent help. At present our knowledge as 



