ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 237 



araneoides, very similar to that described by Eay Lankester in 

 Limulus and various other Arachnids. In Galeodes it consists of a 

 number of coiled glandular tubes, the epithelial wall of v^^hich is 

 formed by a layer of cylindrical cells, at least four times as high as 

 broad ; the protoplasm, of which a fourth or a fifth of the cell is 

 formed, is sometimes limited by a distinct membrane. The rest of 

 the cell is composed of a refractive, radially striated mass ; the lumen 

 of the tube is partly filled by granular matter, which appears to be 

 degenerated protoplasm. 



The author adds that he has failed to find any trace of coxal 

 glands in Epeira corunta, E. diadema, Lycosa sp., Cluhiona pallidula, 

 Marpissa mucosa, or Argyroneta aquatica. 



6' Crustacea. 



Spermatogenesis in Decapod Crustacea.* — A. Sabatier has 

 especially studied Astacus, Carcinus, Crangon, Pagurus, and Scyllarus, 

 but the facts observed were so uniform that be cannot doubt that 

 what he saw will hold good for the whole group. 



Taking Astacus, be found that some of the nuclei of the wall of 

 the testicular culs-de-sac underwent direct segmentation, increased in 

 size, became spherical, and projected into the cavity. These nuclei, 

 which are composed at first of a homogeneous protoplasm with a 

 central nucleolus, soon grow considerably, and exhibit a plexus of 

 chromatin-grains ; the zone of protoplasm which surrounds them is 

 at first barely visible but gradually thickens. Thence result large 

 cells, with large nuclei, which invest the wall of and almost fill the 

 cul-de-sac. These are protospermatoblasts formed by the direct 

 division of the spermatogonia. 



In each protospermatoblast several chromatin-grains appear in 

 the protoplasm ; these fuse, and so give rise directly to several 

 refractive and homogeneous masses; these deutospermatoblasts un- 

 dergo direct division ; they grow, become spherical, and form in time 

 the spermatozoa. While this is going on the nuclei of the proto- 

 spermatoblasts become pale and atrophy ; the cellular body under- 

 going disaggregation, the deutospermatoblasts are set free. At a 

 later stage all the nuclei of tbe protospermatoblasts are found to 

 have disappeared, and the cul-de-sac is filled with deutospermato- 

 blasts imbedded in a granular medium, which contains no chromatin 

 and is formed by the debris of the cell-body of the protospermato- 

 blast. 



The maximum size of the deutospermatoblasts is • 02 mm. ; the 

 chromatin is at first diff'used, or, tbe nucleus is not yet differentiated ; 

 this appears by gradual condensation ; highly refractive granules 

 appear in the surrounding protoplasm, which at the same time 

 rapidly loses its colour. The nucleus becomes flattened, undergoes 

 some migrations, gradually atrophies, and finally disappears. A 

 corona of protoplasmic prolongations completes the spermatozoon. 



The author points out that the view of Grobben and others that 



* Comptes Eendus, c, (1885) pp. 391-3. 



