396 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
between tbe Sarcosporidia and Amoebidium Cienkowsky. It is an internal 
parasite of Cliydorus sphsericus O. F. Muller — a Crustacean belonging to 
tbe family Lynceidue and order Cladooera — which occurs in the ponds 
in the woods of Bellevue, near Paris. One part of the life-history takes 
place in the cavity of the body, where rounded young forms increase in 
size, become ovoid and almost crescent-shaped, show great nuclear multi- 
plication, and acquire a thick and resistant envelope. The division of 
the protoplasm is effected slowly, but the result is a cyst with numerous 
ovoid or spindle-shaped corpuscles, which doubtless correspond to the 
reniform bodies of the Sarcosporidia. They probably infect other indi- 
viduals after tbe death of their host. Within the tissue, however, on 
the dorsal surface of the gut, another phase of the history has its seat. 
Elongated cylindrical forms occur, with fewer and larger nuclei than 
the free forms, and without their refractive and fatty globules. They 
probably increase the infection within the individual host. 
As this new type shows a close resemblance to Amoebidium, an ecto- 
parasite of freshwater Crustacea, the authors propose to include the 
latter along with Coelosporidium in a new sub-order of Sarcosporidia. 
They suggest that Amoebidium is an exceedingly primitive form, and 
they point out the interest of the double developmental cycle in their 
new type. Dimorphism seems to be very general in Sporozoa. 
Two biological facts are of much interest, (a) All the infected 
Crustaceans were non-reproductive ; there seemed to be parasitic castra- 
tion ; (b) the parasite is confined to this particular species. 
Gregarines of the Cricket.* — L. Cuenot has found two new species 
of Diplocystis (D. minor and D. major) and a new Clepsidrina (O. gryl- 
lorum) in Gryllus domesticus. He showed experimentally that crickets 
are infected by eating other crickets with ripe spores ; the sporozoites 
take up their position in the epithelium of the mid-gut, and the cycle 
recommences. The author notices the “ positive cytotropism ” expressed 
in the association of the Gregarines in pairs, and what seems like a 
micronucleus. When two individuals unite before sporulation, the 
membranes persist on to an advanced stage, so that there cannot be 
any karyogamic fertilisation. The nuclear phenomena of sporulation 
include (1) degeneration of the macronucleus, which loses its membrane 
and nuclear sap, while the central karyosome slowly dissolves in the 
cytoplasm; and (2) the division of the micronucleus (in a manner 
midway between the mitotic and the amitotic fashion) to form the 
archispores. 
Double Use of the Name Diplocystis. j — B. Cuenot notes that in 
Schaudinn’s Heliozoa in the new ‘ Thierreich,’ a genus is recorded 
as Diplocystis Penard (1890). The name was, however, applied in 1887 
by Kiinstler to a Gregarine found in the body-cavity of Periplaneta 
americana. Only one species, D. Schneider i, was noted ; and as it was 
not re-observed, the validity of the genus has been doubted. But Cuenot 
has recently found two coelomic parasites in Gryllus domesticus which 
evidently belong to Kiinstler’s genus. Therefore Diplocystis Penard 
must be changed. 
* Comptes Rendus, cxxv. (1897) pp. 52-4. 
t Zool. Anzeig., xx. (1897) pp. 209-10. 
