68 SUMMARY OF CURRENT RESEARCHES RELATING TO 



between division and budding. An interesting phenomenon was some- 

 times observed, that after the usual protrusion of protoplasm, and after 

 the nucleus had begun to go ahead in its changes, a stoppage occasionally 

 occurred, the nucleus retraced its steps, and everything returned in 

 statu quo. 



The author concludes by comparing bis results with those obtained 

 in other Protozoa, and shows that a considerable manifoldness in the 

 details of indirect division must be allowed to occur. 



Diplocystis Schneideri.* — Prof. J. Kiinstler gives an account of an 

 aberrant Sporozoon which has been found in the body-cavity of Peri- 

 planeta americana, and which appears to be the representative of a new 

 genus. It is milky white and opaque, and may therefore be easily seen ; 

 the adult individuals may be as much as 2 mm. long. The body is 

 spheroidal and monaxial, and has at first sight the appearance of two 

 monocystid Gregarines united by their corresponding extremities ; each 

 half has its own membrane, and the wbole is surrounded by a general 

 envelope, wbich extends from one to the other without penetrating into 

 the plane of separation. This membrane is double, but it is probable 

 that the outer of the two has been formed by the host, while the inner 

 corresponds to the cuticle (or epicyte of Schneider's terminology) ; the 

 inner membrane is fine and transparent. The author is inclined to 

 disagree with Schneider and Biitschli as to the superficial nature of the 

 cuticular stria? of Gregarines, and thinks them to be due to the minute 

 structure of the cuticle. In the new genus the markings are certainly 

 not regular. 



Under the cuticle there is a delicate layer of dense protoplasm, 

 which is doubtfully compared with ectoplasm ; it is transparent, finely 

 dotted, and scarcely thicker than the cuticle. It entirely surrounds 

 each of the two vesicles of which the body is made up, and forms 

 the septum between them ; but, as it is single, and as delicate here 

 as elsewhere, it is clearly not due to fusion, but is the continuation 

 pure and simple of the peripheral layer of the body. The internal 

 protoplasmic mass, which must be regarded as the endoplasm, if the 

 other homologies are correct, is more or less, but never completely, 

 fluid, and is filled with special granulations. When the animal is 

 treated with potash or other reagents which dissolve the granulations, 

 the endoplasm is seen to have a reticular structure. The granules 

 present some of the reactions of amyloid bodies. The structure of the 

 nucleus recalls that of true Gregarines, but a difference from polycystid 

 Gregarines is to be found in the fact that each vesicle has a nucleus or 

 body analogous thereto. 



The author gives an account of the formation of the nuclei, and of 

 the development of Diplocystis ; as to its systematic position, he believes 

 it to be an aberrant type, showing affinities both to the Gregarinida and 

 the Coccidia. 



* Tablettes Zoolog., ii. (1887) pp. 25-66 (1 pi.). 



• i = ^=-+- 



