. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. SEMEN. 495 it lengthwise until they perforate the exter- The thickness, on the other hand, is compa- nal enclosure at one end, and now gradu- ratively only slight, being most considerable in the centre, whence the fibre gets gradu- Fi°. 383. ally thinner towards both ends. Kulliker describes, in the spermatozoa of Iphimedia and Hyperia, a thicker cylindrical and oval end, like a peculiar corpuscle. V. Siebold does the same with regard to Asellus aqua- ticus. We believe, however, that such an Fig. Developement of th
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. SEMEN. 495 it lengthwise until they perforate the exter- The thickness, on the other hand, is compa- nal enclosure at one end, and now gradu- ratively only slight, being most considerable in the centre, whence the fibre gets gradu- Fi°. 383. ally thinner towards both ends. Kulliker describes, in the spermatozoa of Iphimedia and Hyperia, a thicker cylindrical and oval end, like a peculiar corpuscle. V. Siebold does the same with regard to Asellus aqua- ticus. We believe, however, that such an Fig. Developement of the Spermatozoa in Mi/sis. (After 'Frey and Leuckart.) ally project outwards (B, c). The number of the fibres thus formed is generally limited to one. We have, however, seen cylinders which contained three or four (c). The formation of the spermatozoa in the radiating cells of the other Decapods, in our opinion, takes place in the same manner. Judging from analogy with Mysis, at least, we cannot share the conjecture of KiiUiker, that the rays would simply drop off and change into spermatozoa. It appears to us much more probable that they are pro- duced, as in Mysis, in the interior of the cell, and that the growing out of rays is merely a secondary event, caused by the circumstance that the spermatozoa formed in the interior urge the external membrane forward with one end, and ultimately pene- trate through it. The projection of the semi- nal fibres, in Mysis, from the cylinder, has indeed much the appearance of their growing out into a thin and long appendix. Thus much respecting the remarkable semi- nal corpuscles of the Decapods. We must still, however, mention the circumstance that the radiating cells in the lower division of the testicles, or in the vas deferens, are generally still enclosed by peculiar spermatophora, like capsules, which possess a round or oval shape, and are often attached, by means of a solid peduncle, in great numbers, one behind another, to one common
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