30 
about the same thickness as the outer, but with a more distinct double 
contour (Mertens, 1892). At two opposite points, usualh^ corres- 
ponding to the poles of the egg, the inner membrane has a small mam- 
millated lyi'oject ion ^ often not apparent. To each of these projections 
are attached a number of clear liyoline fibers^ resembling elastic fibers 
in appearance, which pass outward through the intermediate substance 
toward the outer membrane. Whether there is any constancy in the 
number of these filaments is not known. Mertens (1892) in observing 
an egg turned on end, saw at one pole as many as 8, converging like 
spokes in a wheel and attaching to the papilla of the inner membrane. 
40 
Fig. 37. — Eggs of H. nana from mouse. Enlarged. (After Krabbe, 1865, pi. 7, fig. 108.) 
Fig. 38. — Egg of H. nai^a from man. Enlarged. (After Bizzozero, 1889a, pi. 4, fig. g'.) 
Fig. 39. — Eggs of JI. nana from rat. Enlarged. (After Grass! & Rovelll, 1892a, pi. 3, figs. 1 and 2.) 
Fig. 40. — Egg of II. nana. Enlarged. (After Mertens, 1892, fig. 1.) 
Fig. 41. — Egg of H. nana from man. Enlarged. (After Linstow, 1896a, fig. iv.) 
Fig. 42. — Egg of H. nana from rat. Enlarged. (After Linstow, 1896a. fig. 4.) 
Beginning at the papillte the filaments pursue an irregular, winding’ 
and convoluted course, gradually becoming more tenuous, but, so 
far as ma}’ be observed, do not branch, and end finally in the peri- 
pheral portion of the intermediate sndstance directly underneath the 
outer membrane. Two layers of slightly difierent appearance may 
often be distinguished in this intermediate substance, an inner portion 
which is clear and homogeneous, free from fibers except where it is 
penetrated by them in the two polar regions, and a thicker outer por- 
tion which is granular and in which the distal ends of the fibers inter- 
lace, forming an irregular meshwork. For a great part of their course 
