58 SUMMARY OF CURRENT RESEARCHES RELATING TO 



are, for the most part, passed out as cysts. A few survive the pupal 

 stage in a half-encysted condition, but it is probable that the infection 

 of the adult fly is usually freshly acquired. The cycle in the fly is 

 similar to that in the larvae, and is in agreement with Patten's account 

 of Herpetomonas muscse domesticce. 



The apparent double flagellum is produced in the course of longitu- 

 dinal division. The new flagellum grows up alongside the old, and is 

 not merely split off from it. 



In encystment the flagellum is not cast off bodily, but is drawn 

 down into the cell by the kineto-nucleus, which moves to a position 

 •either alongside of, or posterior to the tropho-nucleus. In this way 

 apparent Crithidia, or even Trypanosome forms, are produced, but there 

 is no hint of an undulating membrane. 



Cristispira and Spirochseta.* — J. Gross describes a peculiar parasite, 

 Cristispira pectinis g. et sp. n., from the stomach and intestine of Pecten 

 jacobseus. Along with Spironema Vuillemin this new genus must be 

 referred to Bacteria — to a new family Spironernacea. The resemblance 

 of Spirochseta to Cristispira and Spironema is not more than superficial. 

 The Spironemacea are described as elongated, spiral, or undulating Bac- 

 teria, with a cylindrical body consisting of a row of compartments. In 

 Cristispira there is a quite unique " crista," which has been called an 

 undulating membrane. Multiplication is by simple constriction, or by 

 the formation of a partition wall, usually preceded by a process of incur- 

 vation. Along with C. pectinis there is another — C. interrogationis sp. n. 



Development of Trypanosoma lewisi in Rat Flea.f — 0. Strickland 

 and N. H. Swellengrebel infected fleas {Ceratophyllus fasciatus) from the 

 rat and studied the development of the Trypanosome. They found ' ; large 

 •oval forms," " round forms," " little ovals," intermediate Critliidise, and 

 small Trypanosomes. The broad fact remains established that T. lewisi 

 undergoes a morphological cycle of development in the gut of its inver- 

 tebrate host. 



New Microsporidian from Termite.J — Cm. Perez found in the body- 

 cavity of a Termite a Microsporidian which he names Duboscquia legeri 

 g. et sp. n. The parasite has a peripheral vegetative zone of budding 

 nuclei, but the elements which are detached towards the interior, instead 

 of forming by division a variable number of naked spores, retain their 

 individuality, increase in size, and are transformed into pansporoblasts, 

 ^each containing sixteen spores. 



* MT. Zool. Stat. Neapel, xx. (1910) pp. 41-93 (1 pi.), 

 t Proc. Cambridge Phil. Soc., xv. (1910) pp. 531-3. 

 j P.V. Soc. Sci. Bordeaux, 1909, pp. 17-19. 



