NOTES KT HKVCK ,:vxvm 



thc cœlonic. Al tlic saiiu' tiinc tlic (^i/slahia incilcs II |iil ln'liinu 



to proliferate, witli llic ii'siil! Ihal a stalk is i'oniird iulo wliicli IIm> 

 parasite commences to inva^inalc ilseli", as il' it vvonJd reacli thc 

 un(lei'lyinj< connective tissue. Tiie distal exli-emity ol' llie stalk tlms 

 becomes expanded, and together witli tlic Grej^arine markfdly 

 resembles an egg-cup containing an egg. Tliere is not llie sliglitest 

 doubt that the parasite is entering and not coining ont. Il is tlie 

 exact reverse of the evagination-pi'ocess met witli in C. irn'uiihiris. 

 The later stages constitnte more an ovcrgi-owing and siirKMiridini:; 

 of the parasite by tlie epithelium and conneclive-tissne of the liost 

 tlian any further inpushing on the jiai-t of Ihe Gregarine ilsrdf, 

 which only rarely occnrs to any exlenl. Thc parasite becomes al 

 length completely encysted and ready for sporulation. 



The adnlts of (\ irref/ularis are perfectiy regniar in form and 

 beautifully ovoid. Owing,ho\vever. to their délicate external laycr 

 (correlated witli whicli is their non-motilily almostthe least tniicli 

 causes déformation, whence hasresnileil. nid"oi'tnnately, tlies|)ecilic 

 naine. In C. irrei/itlaris the two associâtes are sometinies separated 

 by a distinct septum and sometimes noi. which is dépendent un llic 

 time of their union. Ineither case, howeve!-, the adnlt couple, — 

 when the union bas proceeded as far as, in thaï pair, it is going to, — 

 présents superficially quite the aspect of a monocystid Gregarine. In 

 C. Miiirhinii we hâve one of the most advanced instances of 

 neogamy yetknown, the fusion taking place almostat the commence- 

 ment of the life-cycle, when the parasites are scarcely more llian 

 sporozoïtes, and comprising an absolute union of the two eylo- 

 phisrns, the nuclei alone remaining distinct. Ilerethe fusion is lon- 

 gitudinal, thatis side-by-side, while in C. irreyidaris it is end-to- 

 end. Thèse variations are very important in connection with a sludy 

 of the gênerai signilicance of association, which will be fully disens- 

 sed in the detailed memoir wdien other Cijslohùie, and aiso l)ipl»riislis, 

 will beconsidered. (1 bave recently come acrossa Diploaislis, appa- 

 rently D. Schneideri oïKunsller. in a new host. Periplanetn nrù'iiln- 

 lis). I will only mention hère that I regard this exlremely precocious 

 association as an adaptation on the part of the parasites to nisinr n 

 SMi7a6/e r/ssoriaao/j, which would otherwise be rendered very dilii-nU 



by theloss of motiiity characterizing thèse codomic forms. Succes- 

 sive phylogenetic steps in the increasing intimacy of the process 

 are seen in D. majoi% D. minor. and U. Schneideri. .Vs I lu.pe lo 



