1909. | _ 'THREAD-WORMS OF THE RED GROUSE. 341 
(9) 7. exrenwaTvs (Railliet), 1898. Syn. S. gracilis McFad- 
yean, 1897, not Leuckart, 1842. This form occurs in the fourth 
stomach of cattle in England, and in cattle, sheep, and goats in 
the United States *. 
(10) 7. capricora Ransom, 1907. From goats and sheep in 
the United States. 
It is noticeable that the parasite occurs only in vegetable 
feeders, and that, whereas it lives always in the stomach or the 
duodenum of Mammals, it chiefly inhabits the ceca of Birds. 
PARASItEs OF 7'RICHOSTRONGYLUS PERGRACILIS (Cobbold). 
Ina female specimen two ameeboid organisms were making 
their way along the body-cavity in the region of the “ ovejector.” 
Each was throwing out rounded pseudopodia, and the distinction 
between the granular endosare and the glassy ectosare was very 
sharp. Another specimen had some refringent bodies, in shape 
like short rows of yeast-cells or fungi-spores, lying in the body- 
eavity (Pl. LITT. fig. 32). 
Lire-Hisrory oF U'RICHOSTRONGYLUS PERGRACILIS (Cobbold). 
The eggs are found in all the earlier phases of segmentation in 
the fluid contained in the intestinal czeca of the grouse, and usually 
attain there a stage of 32 or 64 blastomeres. Removed from the 
body and kept in a watch-glass in water at the temperature of a 
warm room they continue to segment until in the course of 
twenty-four hours the larve, typically coiled in the egg-shell 
(Pl. LI. fig. 23), are found. A shght pressure on the egg-shell 
causes a rupture, the shell instantly contracts (compare fig. 24 
with fig. 23 on PJ. LI.), and the larva begins to come out. 
Exactly similar stages of development are found in the feces 
of the grouse, both in the rectum and after leaving the body, and 
the ova containing the coiled embryos of the Trichostrongylus are 
common in grouse-droppings. A microscopic examination of 
these droppings reveals a wonderful collection of objects. In one 
specimen alone we found (1) moss-spores and undigested moss- 
capsules, (2) bits of Spirogyra, (3) diatoms, (4) the hyphee of 
some fungus, (5) undigested epidermal cells showing stomata 
from a leaf, (6) spiral woody fibres, (7) bacteria, (8) portions of 
feathers, (9) the leg of a spider, (10) specimens of dAmeba or of 
ameeboid organisms, (11) cestode eggs, (12) eggs and the head- 
end of Trichosoma longicolle Rud., (13) eggs with larva of Z’richo- 
strongylus pergracilis (Cobbold), (14) erystals which are the same 
as those which abound in the ceca. Two kinds of these are 
abundant, one resembling the Charcot-Leiden crystals, the presence 
of which is usually associated with parasites in the intestine, 
the other resembling the crystals of magnesium ammonium 
phosphate, Mg(NH,)(PO,), 6H,O. Doubtless further search would 
* B. H. Ransom, U.S. Dept. Agric., Bureau Anim. Industry, Circular 116, 1907. 
