

Within many of them were the young Plan 

 about, from one to three individuals 

 in each capsule, in others the same 

 were again enclosed within a similar 

 oval case without stem, and again 

 • others were, found with their tip 

 broken off and empty. The greater J ( 



number of them were covered around J " ' K a 



their tip with bluish (colorless in Fig. 2. — a, eggcajwule with a 



alcoholic Specimens) ten-pin-shaped I'll, enclosing two encased embryos: 



tubes with open tips. As these ^'^ , "'^.^ " , ,' Ji'Vui 1-" ~ 

 tubes were invariably on or near th ' [\ n \ V !' *" Vi ! in.V t'i/ 1 

 tip of the capsules only, they cannot oj- - > • • ncl «ing three young 

 be taken for parasitic organisms, ! 



may presumably be openings for an wU reeem Py cases 

 exchange of oxygenized water for the enclosed offspring. Those 

 capsules having no such tubes, probably got them rubbed off 

 through the motions of the gills of the Limulus. A few speci- 

 mens of this Planarian, from three to five millimeters in length, 

 the size usually found only within the capsules, were amongst the 

 larger ones creeping around. These must have just left their pro- 

 tecting homes.— Carl F. Gisslcr, Ph.D. 



Eyeof Planarians.— Professor R. Hertwig finds that the nervous 

 system of these worms is very primitive in character, and is but 

 slightly separated off from the surrounding tissue; in the eye it 

 is possible to distinguish a black pigmented and a clear colorless 

 portion. The former lies along the animal's axis ; the latter is 

 just below the epithelium, and is only separated from it by the 

 basal membrane. The pigmented portion, again, consists of two 

 parts, a transparent nucleus (vitreous body) and a superficial layer 

 of surrounding pigment cells, which are only wanting at the dia- 

 phragm-like point at which the retina or colorless part is con- 

 nected with the rest. The cylindrical fibers of the vitreous body 

 are arranged parallel to one another, the nucleated ends being 

 nearest the pigment. The retina is only formed of optic cells, 

 which are continued at one end into a nerve-fiber, and at the other 

 into a rod- like process. The fibers of the optic nerve traverse 

 the retina in a very irregular manner, so that there is no regular 

 arrangement of the optic cells. 



recent illustrated paper, entitled " Observations upon the Hippo- 

 potamus," by Professor H. C. Chapman, published m the Proceed- 

 ings ofthe Academy of Natural Sciences «,f Philadelphia, the author 

 g'ves a resume of what has been published upon the general anat- 

 omy of this animal, of which he dissected an adult male and female 



