Archive image from page 507 of The cyclopædia of anatomy and. The cyclopædia of anatomy and physiology cyclopdiaofana0401todd Year: 1847 Spermatozoon of Helix pomatia. easy spiral windings are also not unfrequently observed at the enlarged body. The mode of formation of these sperma- tozoa can usually be traced without any great difficulty. It usually takes place in the same way as in the animals already described, as proved by Kollikcr''s excellent researches. Even in the Gasteropods we may observe the deve- lopement of the spermatozoa in the interior of particular vesicles. The arrangement
Archive image from page 507 of The cyclopædia of anatomy and. The cyclopædia of anatomy and physiology cyclopdiaofana0401todd Year: 1847 Spermatozoon of Helix pomatia. easy spiral windings are also not unfrequently observed at the enlarged body. The mode of formation of these sperma- tozoa can usually be traced without any great difficulty. It usually takes place in the same way as in the animals already described, as proved by Kollikcr''s excellent researches. Even in the Gasteropods we may observe the deve- lopement of the spermatozoa in the interior of particular vesicles. The arrangement of these parts only exhibits some deviation. In Helix or Clausilia, in which the stages of this mode of developement can best be ob- served amon< our native snails, we meet with in the interior of the testicle, besides the de- veloped spermatozoa, numerous larger and smaller aggregations of vesicles (in number varying from ten to forty), which are seated on the external surface of a round or oval globule (fig. 358.), which is in diameter T5-/// to '. On a nearer research, it will be found that this globule is not a cell, as one might sup- pose at first sight, but merely a mass of a Fig. 358. Group of vesicles from the testicle of Helix pomatia. tough substance, in which a number of small brown granules are embedded, exhibiting a great similarity with the yolk molecules from the eggs of Helix. There is no external en- closure around this globule. The periphe- ral vesicles or cells, which adhere to it fre-
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