. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. SEMEN. 493 The tlifferencesr in the form and develope- ment of the spermatozoa of lulus fabu- losus are very interesting. The formation of these parts does not confine itself, as in lulus terrestris, to the mere metamorphosis of the nucleus into spermatozoa. Previ- ous to the latter projecting over the ex- ternal surface, the cell membrane gets en- larged on the opposite side (fig, 378. A, B, c) into a corpuscle, which assumes the Fig. Spermatic cells of lulus fabulosus. same shape as the nucleus. The sperma- tozoa
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. SEMEN. 493 The tlifferencesr in the form and develope- ment of the spermatozoa of lulus fabu- losus are very interesting. The formation of these parts does not confine itself, as in lulus terrestris, to the mere metamorphosis of the nucleus into spermatozoa. Previ- ous to the latter projecting over the ex- ternal surface, the cell membrane gets en- larged on the opposite side (fig, 378. A, B, c) into a corpuscle, which assumes the Fig. Spermatic cells of lulus fabulosus. same shape as the nucleus. The sperma- tozoa in I. fabulosus do not, therefore, con- sist in one short cone, but rather in two such formations (fig. 378. D, E, F), which are turned towards each other with their broad surfaces partially touching. One of these is not unfrequently distinguished from the other by a more considerable size- In a developed state, when the original cell membrane, in which the cone was formerly imbedded, has disappeared, the two parts sometimes separate, each having a perfect resemblance to the spermatozoa of I. terrestris. V. Sicbold, to whom we are indebted for the first accurate statement respecting the Chilo- pods*, was not acquainted with the developed forms of these parts in I. fabulosus. He de- scribes as such the stages of developement of the spermatic cells illustrated by us in fig. 378. AtoE, comparing them with the shape of snuff-boxes, in which the lower surface is much thickened, whilst the upper surface contains in the centre a roundish nucleus. The spermatozoa of the Chilognatha f are filiform and of a very considerable length and thickness ; e. g. in Geophilus, where they mea- sure \\"''. Towards one end they gradually become finer, and usually rather undulating or spiral, particularly at the anterior thick part. In Geophilus these fibres are rolled up separately into one ring-like curl ; in Scolopendra, on the other hand, they are straight, and united in small numbers into
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