SOME PARASITES OF SIMULIUM LARV.K. 3OJ 



fixing and staining, and in the end \vas exclusively used. It 

 was also used hot. 



The chief advantage of both of these fluids was that. besides 

 giving excellent histological preparation, they cau-ed tin- hi^to- 

 blasts to turn milky white so that their position and form could 

 be readily observed immediately after the specimen- \\erc killed. 



Staining. Heidenhain's iron haematoxylin combined with 

 orange G was almost entirely used as it gave the U>t diftVr- 

 entiation, though -tamiim \\a-ratherslow. Replacing orange G 

 with i-o-iii (crated staining but differentiation \\a-le 



Mi KMI- SP. I'AK \-i n/iNi, SIMII.H M L\K\ i. 

 \ number of larx.e were placed in a jar of water and left 

 over niijii. The following morning I was -urpri-ed to 

 -e\eral white worm- mo\in- about at the bottom of the jar. 

 h was c\ident that the-e had o.me out of tin- SiniitHnm 

 larvae, SO I went OUt to a ripple W lien- the lar\ a- were particularly 

 abundant and examined the colonie- on & Mia! Stones. I then 

 noticed the large size o| man\- indixiduaU. and on examining 

 these I loiniil that manv of them liad a \\orni coiled up \\ilhin 

 the abdomen I'latc I . I - When a <|iiaiititv of material 



\\a-luon-lii i in o i IK- laboratory it \\.t- found that the-e para-^iti/' d 

 larxa- were much more -In j>h than their lieabhv companion-, 

 \\hicli iapidl\ explored the iar in \\hiih tlp-\ were oiiliiu-d. 

 \\ith their peculiar loopi: ;. The para-iii/ed indi\ idual-, 



h<i\\e\ ( i. seemed mm h Ic-- concerned as to their new -nnouiid- 



iirc-. and maii\ o| them \\eic ~oon motionle--. -laiulin^ tipri^ln 

 on the boiiom and -ide-, of tin- jar with tlu-ir rakes expanded, 

 iad\ to caich aii\ lood which mi-lit lloat tlieir way. Mere 

 i- a po--ible explanalion of their larger size. <)\\in- (,, their 

 curiou> form of feeiliir^ it i- e\i.|ent that the more >hi^i-h an 

 in.li\idual i- the more f ..... 1 it can obtain, and -.liould it .^row 

 bin a little larger than it> companion-, it will reach abo\ e their 

 innumerable oiit-t retched rakes, SO that its food Mipplv will be 

 \ ei \ matciially inrrea-et 1. 



It mu>t not ho\\e\er be taken for granted that all |iara-ili/e<] 

 larxa' \\erelaixcr than their lu-alth\- companion-, for -o me re- 

 mained i|iiite -mall, \\heiva-, main' of the larger lar\a- -lio\\e,| no 



