REVIEW — TROPICAL MEDICINE, ETC. 205 



Martin^ has described in French Guinea a curious form of trypanosome, T. houeti, in a Trypano- 

 lizard, which, to judge from the drawings of fresh preparations, must be difJicult to recognise soraiasis— 

 as a trypanosome. It is a mass of protoplasm with amoeboid movements and characteristic cmitinued 



movement of the undulating membrane. The flagellum does not appear to be longer than 

 the body. Motion is restricted. The nucleus and centrosome are difficult to distinguish. 

 In stained specimens the nucleus is seen to be spindle-shaped and more or less curved, while 

 the centrosome is found to be situated at one of the ends of the spindle. It would seem 

 that the undulating membrane is the most characteristic portion of this parasite, which is 

 altogether peculiar. 



Marchoux and Salimbeni- have found in a tree-frog of Petropolis another strange 

 trypanosome, not of the T. rotaforinm type. The name suggested for it is T. lorelli, and it 

 is not unlike the T. boneti just mentioned. Its nucleus is spindle-shaped and has the 

 centrosome situated at its anterior extremity. 



Brief reference to these, and to most of the other trypanosomes described up to the end 

 of 1907, will be found in Sambon's special paper in the last edition of Manson's "Tropical 

 Diseases." Attention has recently been drawn to what is called the axial filament in 

 trypanosomes. This was described by Eobertson^* in T. brucei as a non-chromatic line, 

 staining a violet blue by Romanowsky running along the long axis of the parasite from the 

 centrosome to the anterior extremity of the body. Moore and BreinP working with wet 

 films and employing special fixing and staining solutious describe, as has been already 

 mentioned under " Sleeping Sickness " (page 175), an intra-nuclear centrosome and various 

 granules near the broad end of the body of the parasite, which they propose to call extra- 

 nuclear centrosomes (blepharoplasts). It is from one of these that the flagellum springs. In 

 T. gamhiense, at certain periods of infection, they also describe what is probably the axial 

 filament of Eobertson which seems first to have been noted by Prowazek. They picture it as 

 a relatively-thick stainable band proceeding from the extra-nuclear centrosome. It is most 

 readily stained by iron haematoxylin, less readily by various aniline colours. It grows from 

 the extra-nuclear centrosome, not along the surface of the animal, but down the interior of 

 the cell towards the nucleus. It is fully twice as thick as the flagellum, and appears near 

 the periods when the greatest number of parasites are present in the blood. 



It may reach or even pass the nucleus ; or it may become coiled upon itself. It seems, 

 however, to become undoubtedly connected up with the nucleus and is evidence of some sort 

 of interaction taking place between the extra-nuclear centrosome and the nucleus. Such a 

 phenomenon, say Moore and Breinl, occurs only among animals in which no evidence of nuclear 

 division or cell division is evident. During the whole development of the stainable band the 

 nucleus remains in a condition of complete repose. It is suggested that the metamorphoses 

 connected with the appearance of the "black line'' is an attempt on the part of the 

 trypanosomes to become sexually differentiated, but this attempt is not completed, the cells 

 reverting to their primary condition, in which case the process could be regarded as an 

 example of a special form of parthenogenesis. In this connection it is noted that at the time 

 of the formation of the black line onlj' a portion of the extra-nuclear centrosome unites with 

 the nucleus. Swellengrebel'* has found the axial filament in T. bnicei, gamhiense and 

 equinmn. The intra-nuclear portion of the axial filament appears to be the centre for the 

 formation of granules which afterwards leave the nucleus in the line of the filament and then 

 disperse themselves throughout the cytoplasm. These granules are specially abundant in 

 parasites which are degenerating and consists of volutine. 



Salvin-Moore, Breinl and Hindle" have recently applied their special methods to the 

 study of the life-cycle of T. lewisi which closely resembles those of T. gamhiense and 



» Martin, G. (April 13th, 1907), " Sur un Trypanosome de Saurien." C. B. Soc. Biol., t. LXII. Quoted in 

 Journal of Tropical Veterinarij Science, November, 1907. 



^ Marchoux, A., and Salimbeni, E. {ihiil.), " Un Trypanosome Nouveau chez nne Hyla Voisine de 

 H. Lateristriga." Ihiil. 



° Eobertson, M. (1906). Proceedings of the lioijal Society, Edinburgh, Vol. XVI. 



* Moore, J. E., and Breinl, A. (December 9th, 1907), "The Cytology of the Trypanosomes." Annals of 

 Tropical Jfedicine and Parasitolvgij, Series T.M., Vol. I., No. 3. 



" Swellengrebel, N. H. (.January 18th, 1908), "La Volutine chez les Trypanosomes." C. R. Soc. Biol., 

 t. LXIV. Quoted in Bull, de riastitut Pasteur, April 15th, 1908. 



« SalvLQ-Moore, J. E., Breinl, A., and Hindle, E. (.July 1st, 1907), " The Life-History of Trypanosoma Lewisi." 

 Annals of Tropical Medicine and Parasitulogg, Series T. M.. Vol. II., No. 3. 



• Article not consulted in the original. 



