39-4: SUMJIARY OF CURRENT RESEARCHES RELATING TO 



mass is subsequently organized into the bud, acquiring a contractile 

 vacuole and four ciliated ridges. 



The area over which the dissolution takes place constitutes the 

 so-called " brood-chamber," but it is not a definite space, and there is 

 no definite opening to the exterior, except at the moment of birth. 

 The orientation, development, and birth of the bud are described. 



Division of the meganucleus of the parent is amitotic. The 

 meganucleus does not possess a true achromatinic nuclear membrane, 

 but the surface layer of chromatin is so arranged as to form a false 

 chromatinic membrane. Division of the meganucleus is always 

 complete before the bud leaves the body of the parent. Division of 

 the micronuclei, on the other hand, is by a primitive kind of mitosis. 

 No chromosomes or visible kinetic centres are present. 



Reference is also made to the migration of the adult from one gill 

 to another, a moribund residuum being left behind. This process may 

 simulate bud-formation, and is either of the nature of an excretory 

 process (as Biitschli suggested) or associated with ecdysis in the host. 

 Attention is called to an area of special cytoplasm which is found in the 

 bud during its formation, but the significance of the structure remains 

 obscure. 



Modification of Spirochsetes.* — Hideyo Noguchi discusses certain 

 alterations in the biological properties of Spirochaetes induced by 

 artificial cultivation. He has succeeded in obtaining in pure cultures 

 the following varieties of the Trepanonema group : — T. 'pallklmn, T. 

 pertenue, T. meter odentium, T. microdentium, T. mucosum, T. caJligyrum, 

 and T. refringens. These retain their structural characters for two to 

 four years, but they may change in vital properties. In the case of 

 T. paUidum the virulence disappeared within about four months after its 

 purification ; a strain of T. pertenue lost its virulence as soon as it was 

 isolated ; the strong odour of T. microdentium gradually disappeared 

 after a year ; the mucin-producing property of T. mucosum disappeared 

 in about five months. The new environments seem to bring about the 

 disuse and functional loss of certain properties. 



Gregarines of Glycera.f— Helen L. M. Pixell-Goodrich discusses 

 the niunerous gregarines which occur in the large Polychffit, Glycera 

 siphonostoma. There appear to be four different forms, including, at 

 least, one species of Gonospora {G. ghjcerae sp. n), which is described. It 

 is surrounded for the greater part of its existence by a layer of host- 

 epithelium. Association is made secure by means of a dovetail an-ange- 

 ment. The spores, under high magnification, reveal a more complicated 

 structure than has previously been described in the genus. 



New Parasite from a Tick. | — Ed. Chatton and G. Blanc 

 describe a new parasite from Ehipicephcdus sanguineus (a tick of the 

 dog, rabbit, etc., found in this case on the gundi, Ctenodactylus gundi, 



* Ann. Inst. Pasteur, xxx. (1916) pp. 1-4. 



t Quart. Journ. Micr. Sci., Ixi. a916) pp. 205-16 (1 pi.). 



% C.R. Soc. Biol. Paris, Ixxix. (1916) pp. 134-8 (2 figs.). 



