DR. NELSON ON THE REPRODUCTION OF THE ASCARIS MYSTAX. 
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internal limiting membrane, f. The nuclear membrane formed at the 
expense of the outermost granules of the nucleus. 
Figs. 24 — 27 . Spermatic cells in various stages, a. The cell-wall more or less pro- 
truded. h. The nucleus, f. The nuclear membrane, which, by increasing 
most at the centre, has forced the cell-wall out. 
Figs. 28 — 30. Spermatic cells, a. The cell-wall recovering its protrusion, h. The 
nucleus, becoming smaller and more surrounded by the nuclear membrane. 
f. The nuclear membrane become tubular and bent by the elasticity of the 
cell-wall. 
Figs. 31 — 34. Spermatic cells, a. The cell-wall now become spherical, c. The 
nucleolus still persistent, f. The nuclear membrane, first cup-shaped, then 
conical, and lastly tubular. 
Figs. 35, 36. Spermatic cells in the last stage, a. The cell-wall. h. The remains of 
the nuclear granules, c. The nucleolus, f. The nuclear membrane, now 
become tubular or flask-shaped, adapting itself to the curve of the cell-wall. 
Fig. 37 . Spermatic particles in a state of imperfect development, h. The nuclei of 
spermatic cells set free. c. The nucleoli of the same. f. The nuclear 
membrane in various degrees of perfection. 
Fig. 38. Perfect spermatic particles, h. The remaining granules of the nucleus. 
c. The nucleoli, f. The fully-formed nuclear membranes or spermatic 
particles, g. Their open mouths. 
Figs. 21 — 38. Magnified 500 diameters. 
PLATE XXVII. Magnified 330 diameters. 
Fig. 39. The commencement of the ovary, a. The csecal extremity, composed of a 
thick, semiopake granular membrane, from the internal surface of which 
the germinal particles are thrown off. h. Apparent invaginations, probably 
formed by casts of the csecal extremity thrown off at intervals, c. The 
solid germinal particles as first thrown off. d. The germinal vesicle formed 
by the swelling up of the external surface of the germinal particle, f. The 
germinal spots or the central portion of the solid germinal particle. 
g. Large opake yolk-granules floating free. h. The delicate homogeneous 
and transparent membrane forming the upper portion of the ovarian 
tube. 
Fig. 40. Portion of the ovary, d. The germinal vesicles, h. The membranous tube, 
giving indications of strise and granules, h. The granules thrown off by 
the ovary to form the vitellus. 
Fig. 41. Middle portion of the ovary, h. The external homogeneous membrane, 
h. The granules contained within. 1. The strise. 
4 G 2 
