l'.)!l).] PAKASiric I'lioi'oxiiA OK i;ko i;iiorsi',. 701 



and strands of the luemljiuue are disposed. Some of these Ijodie.s 

 a.i-e not unlike Eberth's original Hgures (1862). 



JSlonoccrcomonas is an ovoid organism possessing fonr fla<'ella at 

 the broad anterior end of the body (fig. 48) together with a nucleu.s 

 and blepharoplast. Sometimes one of the flagella trails backward 

 (fig. 47). Oil one occasion a Afouocercomonas form with a suggestion 

 of a rudimentary membrane, axostyle and granules was seen 

 (tig. 47). If such a parasite be normal and not deformed, then it 

 would be an intermediate form between Trichomonas and 

 Monocercomoiias (cf. Martin and Ilobertsi^n's fig. 8). 



(b) SpirochaetaGea (Proflagellata). 



Spihocii ETA i.ow-i'n, sp. n. 

 (Plate LXI. figs. .51 .57.) 



When fresli oa^cal contents of certain grouse of various ages 

 were examined microscopically, small active organisms have been 

 seen, moving among the food debris and flora found in the gut. 

 These organisms are Spirochsetes, and their presence in the Ccecal 

 contents of grouse has also been noticed by Dr. Cobbett in adult 

 grouse, and by Dr. Leiper in a young grouse chick. I have 

 sometimes observed the Spiroch;etes in the hinder part of the 

 intestine as well as in the caeca. 



Having had the opportunity of observing this Spiroclu\?te, 

 which I have named Sjnrochceta lovati, I append a few details 

 regarding its life-history and structure. I may say that the 

 parasite does not appear to have a veiy deletei'ious efiect on its 

 host. 



The organism, as observed in life, occurs in crecal contents, 

 where it is mingled witli semi-fluid food materials, and is often in 

 company wdth many minute, I'od-like bacteria, both free and 

 in colonies, and also small hyphal threads, evidently of some 

 fungus. Because of its associations, the Spirochsete is by no 

 means easy of observation, and much dilution of the ca?cal contents 

 to facilitate observation only hastens the death of the Spirocha^te. 

 Further, in fixed and stained preparations the Spirocha-te itself 

 takes up the stain somewhat faintly. 



The movements of the Spirochsete are active and resemble those 

 of the Spiroch;"etes of Lamellibranchs (ovsters, fresh-water mussels, 

 Tapes) which I have already described (1907, 1908, 1909). " The 

 motion appears to be resolvable into at least two components : 

 (i) An undulatory flexion of the bod}', mainly for progression, 

 and (ii) a spii'al or corkscrew movement of the body as a whole, 

 due to the winding of the membi-ane." S. lovati has a small, but 

 distinct undulating membrane best seen in stained preparations 

 (PI. LXI. figs. 51-57). The ends of the organism aie pointed, the 

 length of the body being from 16"5 /j. to 3'2-5 /.i. 



In some very narrow foi-ms the relatively long body may be 

 throAvn into many waves (fig. 53), but usually four to seven waves 



Proc. Zool. Soc— 1910, Xo. XLVI. ' 4(3 



