|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Quarterly Journal of Microscopical Science, Vol s2-79, 309-335, Copyright © 1936 by Company of Biologists
1 Department of Zoology, University of California, Berkeley, California
1. The previously published description of Pseudodevescovina uniflagellata from Kalotermes (Neotermes) insularis is incorrect in practically all points. The flagellate is a devescovinid which, like other members of the subfamily, has three anterior and one trailing flagellum. The trailing flagellum is relatively small and slender.
2. The most unusual characteristic is the parabasal apparatus, which consists of a C-shaped or L-shaped main limb adjacent to the nucleus and seven to nineteen cords attached to the transverse portion of this.
3. A sinuous movement of the cresta has been observed in living material.
4. The flagellate moves forward steadily with considerable vigour as compared to Devescovina lemniscata and even Stephanonympha with its hundreds of flagella. Yet the small trailing flagellum seems to be the main cause of this movement, as the anterior whip often is turned back against the body and trailed. This suggests that increase in size of the trailing flagellum, which is a broad ribbon in Devescovina lemniscata, or increase in number as in Stephanonympha, does not necessarily enhance the locomotor efficiency of the flagellate.
5. The body is completely covered with a dense investment of relatively short spirochaetes, the ends of which appear actually to be embedded in the cytoplasm and, taking an iron-haematoxylin stain, simulate basal granules.
6. There are eight chromosomes, which can be recognized most clearly when they are granules or short, stout rods in the early telophase.
7. At the beginning of binary fission, the main limb of the parabasal apparatus breaks. A portion of length about equal to that of the nucleus is left attached to the centriole at one pole of the spindle; at the other pole a parabasal develops de novo, doubtless in connexion with the centriole. This is at first a filament, which reaches a size equal to the part of the old parabasal that remains attached, then both grow equally. After division of the body, new cords grow out from this main limb.
8. The detached part of the old parabasal apparatus breaks up into successively smaller vesicular bodies, which are noteworthy for a deeply staining cap sharply distinguished from the chromophobe substance, appearing like diagrams of dictyosomes. These fragments are resorbed before plasmotomy.
9. Grassi's Devescovina nova has been found in the species of termite from which he described it, Kalotermes (Neotermes) erythraeus from Eritrea. Its characters indicate that it must be removed from Devescovina, and it has been placed in the genus Caduceia.
10. The parabasal apparatus consists of a main limb, which in this case is loosely spiralled around the trunk of the axostyle, and from one to six attached cords directed more or less parallel to it.
