1-lt^-i Journal of Applied Microscopy 



mature non-nucleated erythrocytes to the nucleated red corpuscles and the 

 remaining marrow cells by taking, with a fine pair of scissors, as nearly as possible 

 equal amounts of marrow about the size of a pin head, and very carefully press- 

 ing them evenly between two clean cover-glasses. With the very cellular 

 lymphoid marrow of the anaemic animal this was always successful, giving a thin 

 smear, a little thicker in places where librin lay about heaps of cells, which did 

 not interfere in a general view over the preparation. The air-dried cover smears 

 were fixed in an alcohol and ether mixture, and stained with Ehrlich's eosin- 

 haematoxylin solution or the triacid stain. In the same manner preparations 

 were made of spleen and in a few cases of the lymph glands also. e. j. c. 



Danjeard, P. A. Nuclear division in Protozoa. I" this paper the author takes excep- 

 Le Botaniste 7, 1900. Extract from Royal tion to the usual Statement that nuclear 

 Mic. Jour. April, looi. ,...._, . . . , , ,. 



division in Protozoa is invariably direct. 



Figures and descriptions of ordinary division as shown in Avuvba polypodia 

 are given ; that of Amoeba crystalligera, in which the dividing nucleus is drawn to 

 a thread at the division plane ; in Sappi/iia pedata in which the nucleus divides 

 twice without cytoplasmic division ; finally a full account of the process of 

 division in Amceba hyalhiia, sp. n, in which no karyokinesis occurs. In this 

 form the nucleus contains a large nucleolus which breaks up at the onset of 

 division and appears to give rise to chromosomes. Some parts of the nucleolus 

 also mingle with the nucleoplasm and give it chromatic properties. This 

 nucleoplasm forms a spindle in which very fine chromosomes arrange themselves 

 in an equatorial plate. Later they separate and approach the poles of the spindle. 

 The spindle is pulled out as they do this, which process is continued as the 

 chromosomes migrate to the poles of the elongating amoeba, until but elongated 

 threads remain to represent the spindle. The author holds this as proof that 

 the chromosomes migrate by their own activity here as elsewhere ; since in the 

 present case no spheres exist and the movement of the chromosomes continues 

 after the poles of the spindle have been reached, the threads of the latter cannot 

 be active agents. As the new cells separate, the chromosomes round themselves 

 off and form the nucleolus, the spindle remains, constituting the surrounding 

 nucleoplasm. This is clearly a karj'okinetic process, but in the author's opinion 

 its simplicity shows that the evident process is merely a modification of the 

 simpler direct division, special emphasis being laid on the conditions occurring 

 in Avui'ba crystalligera. a. m. c. 



Penard, E. Dr. Experiments in Diiilugia, ^^r. Eugene Penard has succeeded in 

 Rev. Suisse Zoo), 8, 1900. Ext. from Jour. separating the nucleus intact from the 

 Roy. Mic. See, April, igoi. , . , , ^ 



cytoplasm in several cases, three of 



which were accomplished without any other material injury to the organism. 

 Such separate nuclei appear healthy for 9 to '1\ hours after removal, but they ulti- 

 mately die apparently of inanition. The non-nucleated portions, however, lived 

 and moved about for several days apparently none the worse for the operation. 

 In three cases the specimens were killed for examination and consisted to all 

 appearances of normal protoplasm. Non-nucleated animals were not seen to 

 take food, but since intact forms can remain without food for weeks uninjured 

 there seems no doubt that the mutilated specimens could digest food. a. m. c. 



