some Parthenoffenellc Cliironomida'. 227 



Juiu> \\K Hctwfou July 5 ami .Inly 1 t al)OUt seventy adults 

 had liatc-licd from tiii'M; larva;, aj^ain all fiMuales ; tlicso, 

 !i};aiu, |)r(){luci'd cj^j^-massi's partluMKJj^euctically, aurl auotlicr 

 j;cuirati()U of Hies (twi-uty sprciuieus, all ft'uialcsj appeared 

 at the cud of July. A tliird parthenogenetically |)ro(iuee(l 

 generation appeared al)out August 20 and a fourth about 

 August .31. i'roui this tiiiu; until early Oetoher fiies and 

 hirvju were almost continually proent (though in deenasing 

 nimhers), so that it Ix-cami; i.mpossiblc to distinguish the 

 s(•^).lrat(• generations ; hut it would he ^afo to say that there 

 were at least five parihenogenetie generations during the 

 year, and though a earefnl watch was kept on the breeding- 

 jar, no males were seen. 



The metamorphoses of Corynoneiira arc well known, and 

 nothing need he said coneerning this speci<^s, except that the 

 fo)d of the larvie app ared to consist of rather large infusoria 

 {Parumrciinn'f) which swarmed in the breeding-jar. The 

 lar\ie could be watched under a lens ap|)arently chasing the 

 infusoria, though I could never be quite certain that they 

 swallowed them. When the numbers ot' the infusoria 

 diminished, the Conjuniwuru larvic also became much 

 sc.ireer. Hoth had (lisappeared entirely by the middle of 

 Octobi r. 



During the summer of 1918 I also reared a small number 

 of mail's and females ot" (Junjnoneura celeri/jes, Winn, (or 

 what I believe to be this species), from the pond which had 

 provided me in 1017 with the first C.ininipla,a.ui\ also earlier 

 with Chironomus c/avalirrus. This species [(Jonjnotieura 

 celeripes), as already mentioned iu the iiitrodnctiou, has 

 been found by Goetghebner to be occasionally partheno- 

 geuctie *, l)ut I could obtain no evidence that such was the 

 case with any of my specimens. Newly hatched females 

 isolated in separate tul)es did not deposit egg-masses, nor 

 did tiicy do so after males had been placed in the tuljcs with 

 them. It would appear that in this locality C. alcrij/es has 

 not the power of parthenogenesis, and the fact that 1 i'ailetl 

 to obtain any eggs at all may be explaineii by the not unlikely 

 assumption that it will not pair except under certain natural 

 conditions. 



'i'he species which I regard as C. celeripes appears to be 



• Since the Kuropean njx'eies of Corynoneura Iiavo not vet been criti- 

 cally studied, it is, of course, possible that (.iootfrliebiier'a species was 

 re illy the same which I have liere described as C. iinnijita, rather than 

 the one I regard as (.'. celeripes. Should that be the case, there is nothing 

 new in my observations, but they would still form an iuterestin)^^ con- 

 tirniation of Goetghebuer's. 



