ON THREAD-WORMS OF THE RED GROUSE. [ Mar. 16, 
Fig. 21. Ege with thirty-two blastomeres. 
22, Ege with sixty-four blastomeres. 
23. Ege with coiled-up larva, ripe for hatching. 
24, A similar egg, artificially ruptured, and the larva in the act of escaping. 
Figs. 
This shows the contraction of the egg-shell when ruptured. 
15-24 inclusive are drawn to the same scale, and the last four or five from 
specimens artificially reared in a watch-elass. 
Puare LIT. 
Fig. 25. A normally hatched embryo, a little older than the stage shown in fig. 23, 
found living in droppings of the grouse picked up on a moor. 
26. A slightly older larva, possibly of 7. pergracilis, found in the lungs of a 
dying grouse. 
27, A similar specimen, still in the fiuid of the lungs, but twenty-four hours 
after it was last seen alive. This explains why they are so easily 
overlooked. 
28. Two amceboid parasites in the body-cavity in the neighbourhood of the 
ovejector. 
29. A female Trichosoma longicolle. Magnified about ten times. (1) Shows 
the cesophageal cells, (ii) the prolapsed vagina, (ili) the uterus with eggs, 
and (iv) the slightly inflated tail. 
Pirate LIMIT. 
Fig. 30. Three specimens of same. Magnified about twice. 
31. The same, magnified about seven times. 
32. Anterior end of the same. More highly magnified. 
33. Csophageal cell. More highly magnitied. 
34. Uterus with eggs and alimentary canal. 
Prats LIV. 
Fig. 35. @sophageal cells, pierced by cesophagus, and showing granular nuclei and 
to} to} ] y ] to} ) oD 
slightly ridged cuticle. Magnified. 
36. Optical section, showing right and left glandular bands. Slightly magnified. 
37. A glandular band seen im profile; the unicellular glands and their ducts 
are dark, the cuticle light. Highly magnified. 
38. The prolapsed vagina. Highly magnified. This view shows also the 
passage of the cesophagus into the intestine and the neighbouring 
glands. 
39. Posterior end of the male, showing spicule partially extruded. Highly 
magnified. 
40. Egg from uterus. Highly magnified. 
41. Ege in contents of intestine of the grouse. 
PrarE LV. 
Fig. 42. Masses of epithelial cells which occur around the 7. longicolle and which 
have been broken off the inner walls of the duodenum. 
43. The same, isolated and more highly magnified. 
44, Nematode larve found, on one occasion, in small intestine of the grouse. 
45. The same, more highly magnified. 
46. Crystals from rectum. 
List of Reference Letters. 
a, 6, c. The three chambers of the ove- | o. Ovary. 
jector. 0.6. Oral butb. 
a.l. Antero-lateral rib. | ce. (Esophagus. 
am. Ameeboid, parasitic organisms. oj. Ovejector. 
an. Anus. ph. Pharynx. 
c.gl. Cephalic glands. p.l. Postero-lateral rib. 
d. Dorsal rib. 7. Rectum. 
e.d. Externo-dorsal rib. r.C. Rectal cells. 
g. Gubernaculum. sp. Spicule. 
in. Intestine. | w.&ut. Uterus. 
lv. Latero-ventral rib. v. Vagina. 
m. Mouth. v.v. Ventro-ventral rib. 
ml 
. Median-lateral rib. 
