Miscellaneous, 309 



Capri, M. Hackel was also occupied with these animals on the shores 

 of Dalmatia, and had likewise ascertained the existence of zoosperms 

 and ova in the calcareous and siliceous sponges *. The results of his 

 researches had even been published a little before the memoir of M. 

 Eimer. The latter, however, thinks Hackel, like Huxley and Lie- 

 berkiihn, had not under examination any completely developed zoo- 

 sperms, but only slightly advanced forms of those elements. As, 

 however, Hackel has observed a direct fecundation, M. Eimer hazards 

 the supposition that there may be some sponges in which the zoo- 

 sperms are arrested at one of the inferior stages of their develop- 

 ment. — Archiv fur mihroskojjische Anatoynie, vol. viii. Heft 2; Bihl. 

 Univ. August 15, 1872, Bull. Sclent, p, 350. 



Investigations upon the Development of the Gregarinae. 

 By E. VAN Beneden. 



The investigations of M, E. van Beneden upon the Gregarina 

 gignntea of the lobster confirm the observations of Lieberkiihn 

 upon the transformation of certain amoeboid forms into Gregarince ; 

 only the phases are here somewhat different from those observed in 

 the Gregarince of the earthworm. The author found, in the small 

 intestine of the lobster, some small, finely granular, protoplasmic 

 masses, destitute both of membrane and nucleus. These masses, 

 which are continually changing their form, greatly resemble Prota- 

 mceba primitiva or P. agilis of Hackel, from which they differ only 

 by presenting fine molecular granulations even to the peripherj', and 

 by never emitting true pseudopodia. According to HackeFs nomen- 

 clature, these would be true gymnocytodes. 



Side by side with these we find small protoplasmic globules, which 

 differ from them only by having lost the faculty of moving and 

 changing their form. They have no enveloping membrane any more 

 than the former ; but their spheroidal form is preserved by a peri- 

 pheral layer of denser and less fluid protoplasm. 



With these globular and motionless forms we find others perfectly 

 similar to them, except that they have one or two prolongations 

 which cannot be assimilated to pseudopodia, but rather to the 

 movable stalk of the Noctiluece. M. van Beneden names these 

 generative eg fades, because it is these which directly give birth to 

 the Gregarina'.. When there are two prolongations, these are 

 inserted at but a little distance apart. One of these prolongations, 

 which is shorter and more slender and with paler outlines than the 

 other, and only contains very fine granules, is almost destitute of 

 mobilitj^ When brought against a hard body, it is seen to bend ; 

 and the bend thus produced persists for a very long time. The 

 other prolongation is considerably longer and stouter, with stronger 

 outlines and a more refractive protoplasm. Besides a very fine 

 punctation, it contains opaque granules, which are very numerous at 

 its slightly widened extremity. This process is endowed with an 

 extreme mobility, which is manifested in two modes. It may 

 swing about like the stalk of the Noctiluece, or present an inflection 

 * Jenaische Zeitschrift, vol. vi. Heft 4. 



