126 PROGRESS OF MICROSCOPICAL SCIENCE. 



gregarina measuring two-thii-ds of an inch in diameter. He found in 

 the intestine of the lobster small masses of protoplasm destitute of 

 nuclei, finely granulated, and performing continuously ordinary amoe- 

 boid movements. These bodies he compares to the Protamoeba 

 primitiva or Protamceba agilis of Haeckel, and classifies them with 

 the true Gymnocytodes of that author. Bodies of precisely similar 

 ajipcarance are also found, however, which are incapable both of 

 locomotion and of change of external form. In these a homogeneous 

 marginal zone and a granulated internal mass come to be distinguished. 

 The gymnocytode invests itself with a membrane, and is thus con- 

 verted into a leptocytode (of Haeckel). Each cytode now thrusts 

 out two arms, which are jDrolongations of its substance, and each of 

 which is destined to become a gregarina. The first one that makes 

 its ajipearance is the largest, and is characterized by its marked granu- 

 lation and great mobility. It detaches itself from the cytode and 

 becomes free. Before this occurs, however, the smaller arm is thrust 

 forth, which is not granular, and is motionless. After the first or 

 mobile arm has separated from the cytode, the second arm becomes as 

 mobile as the first was, and absorbs the whole body of the cytode into 

 itself, just as the embryo of a mammal absorbs the contents of the 

 yelk-sac. The two protoplasmic arms thus produced from a single 

 cytode — Pseudofilaria, as Van Beneden terms them — move with extra- 

 ordinary vivacity in the intestine of their host. After the lapse of a 

 certain time the movements become less lively ; the pseudofilaria 

 become shorter and thicker ; nucleoli, and subsequently a nucleus, 

 make their appearance in their interior. At a still later period a 

 homogeneous cortical layer (membrane) is differentiated from the 

 granulated contents, at one pole of which strongly refractile granules 

 collect, and the whole organism now appears as a well-defined small 

 gregarina, which soon augments in size. 



Laboratory for Marine Zoology. — Dr. Anton Dohrn, in a letter to 

 Professor Agassiz, who has communicated it for publication in the 

 'American Naturalist' (January, 1872), writes that he has matured. a 

 plan which has for many years been in the minds of many zoologists ; 

 that of establishing a large laboratory for marine zoology in the 

 Mediterranean. He has obtained permission of the authorities of the 

 city of Naples to construct a large building at his own expense, in the 

 Villa Eeale at Naples close to the sea, containing a large aquarium 

 for the public, and extensive rooms for naturalists of every country. 

 Dr. Dohrn, with two or three other German zoologists, will settle 

 there and conduct the administration of both the aquarium and the 

 laboratories. He wishes that information regarding this lj)roposed 

 laboratory be widely extended, and earnestly invites all who may go 

 to Naples to visit the aquarium. An annual rej^ort of the work done 

 and progress made at the zoological station will be published." A 

 committee has already been formed to give further dignity and im- 

 portance to the project, consisting of Messrs, Hemholtz, Dubois- 

 Reymond, Huxley, Darwin, Haeckel, Leuckart, Van Beneden, &c., and 

 in America Professor Agassiz, 



