SOME PARASITES OF SIMULIUM LARV.l , 



* 



formed by one of tin- worms, which could not then be Mcrmis 

 but must be a new form closely related to Allanioncnm or Sphfc- 

 rnlaria, in the females of which the uterus becomes protruded 

 and is finally many time- the -ize of the original worm. 



I naturally visited the >t ream in order to obtain more specimens 

 suffering from this disease, only to find that a quantity of oil 

 which had been flowing down tlu--tn-am for someday- pa-t had 

 succeeded in killing off all the larva,- in that neighborhood. It 

 wa.s then-fore necessary to find a place further up the -m-am, 

 aborr the contamination, where the larva- were li\inu. About 

 1 1. ilf a mile'- \\alk led to such a place, -i mated under a -tone arch, 

 in which the larva- were present literally in thoii-md-. They 

 forim-d greal masses covering the whole -nrface of the rock-. An 

 ninaiion of a few rocks soon showed that the .\[<rniis \\ a- \ cry 

 plentiful lii-re, but it was some time before I found -pecimen- 

 \\ith 'In- ctiriou- white abdomens for which I \\a- -earchin^. I 

 (haii-i-d. h"\M\er, to pull up a piece of water weed that ua- 

 llo.it in^ in a -u if 1 1\ running swirl and here I found quite a number 

 of individual-, -miie showing immense abdominal swelling- dm- 

 to the parasite. On examining a few small specimens I found thai 

 the para-iie was more numerous among them than annui- the 

 lai-.i i indi\ iduals; a closer examination of the rock* showed that 

 the-e -mall parasitized individuals were quite commonly scattered 

 amon- the larger healthy ones. A quantity of material \\a-> 

 taken back to the laboratory to be studied on the -anie line- as 

 that adopted for the .UVrw/s parasite. 



K\u KNAI. EFFECTS ON THE L.\RV\. 



The iir-t effect IK 't iced in badly infested larva- i- the immen-ely 

 distended abdomen. In some cases as in that illn-trated in 

 I'lati- \ .. I Ig. u. i he a]i-x of this region of the body was thn-e 

 to four time- it- normal size. Unlike the .\fcnnis, thi> ])ara<it- 

 is not contin.-d to the \entral portion of the bod\- but entirely 

 surrounds the caudal extremity of the me-eiiteron. and -mall 

 deiached colonies were not infrequent in the thoracic re-ion. 

 I'he Malpi^hian tubule-, however, can usually be seen on the. 

 surface of the ma and are plainly vi-ible through the tightly 

 Stretched skin, \\hidi is ( |uiie transparent in place- and appears 

 to be on the point of bur-ling. 



