212 THE GROUSE IN HEALTH AND IN DISEASE 



The ova are laid in the fluid contents of the host's cseca in which they are 

 frequently found floating. We have found developing ova in the cseca of a young 

 Grouse chick of seven to ten days of age from Auchentorlie, Dumbartonshire. 

 Apparently the cseca are the chief centres of absorption of the digested food ; they 

 contain none of the cellulose skeletons of vegetable cells so common in the intestine, 

 and none of the masses of cast epithelium which make up so large a proportion of 

 the flocculent masses in the duodenum. The eggs may develop further inside the 

 caecum, though as yet we have not found an egg containing an embryo in its contents. 



A small pellet of the csecal contents, such as can be carried away on 

 the point of a needle spread out under a cover-slip, will, in a well infected 

 bird, show some twelve to twenty worms and one hundred to two hundred 

 eggs in the field of a two-thirds inch Ross's objective with a No. 2 eyepiece. 

 Allied In his Memoir on the genus Trichostrongylus, Looss enumerates 



species. tne f u ow i n g f our species : 



(1) T. RETORT^EFORMIS (Zeder), 1800. From the duodenum and exceptionally 

 from the stomach of Lepus timidus and Lepus cuniculus (when undomesticated). 

 Railliet says it coexists with Strongylus strigosus, and helps to give rise to a per- 

 nicious anaemia. It develops directly without intermediate host. 



(2) T. INSTABILIS (Railliei), 1893. Syn. T. subtilis Looss, 1905. From the 

 duodenum and exceptionally from the stomach of Ovis aries, Ovis laticauda, 

 Antilope dorcas, Camelus dromedarius (Egypt), Papio (Cynocephalus) hama- 

 dryas (North Africa), and occasionally in Man (Egypt and Japan). Railliet states 

 that this species, together with Hcemonchus contortus, lives in the duodenum of 

 sheep which succumb to pernicious anaemia. 



(3) T. PROBOLURUS (Railliet), 1896. From the duodenum of Ovis aries, Ovis 

 laticauda, Antilope dorcas, and occasionally of Man (Egypt), and Camelus 

 dromedarius (? Paris and Egypt). 



(4) T. VIBRINUS Looss, 1905. From the duodenum of Ovis aries, Ovis 

 laticauda, occasionally from Camelus dromedarius and Man (Egypt). Looss 

 regards this as a rare species. 



To these must be probably added : 



(5) T. TENUIS (Eberth), 1861. Syn. S. tennis (Mehlis) Eberth, 1861. From 

 the caecum of the goose, Anser cinerea, and 



(6) T. NODULAXIS (Rud.), 1809. Syn. S. nodularis(Rud.), 1809. Syn. A scaris 

 mucronata Frohlich, 1791; S. anseris Zeder, 1800; S. nodulosus Rud., 1803; 

 crispinus Molin, 1850. From the mucous and muscular coats of the stomach and 



