continued 



KEVIEW — TROPICAL MEDICINE, ETC. 153 



Theiler' reports efforts in the case of East Coast fever to produce a serum which has Bovine 



no haemolytic action on the blood of sick animals, and acts as a preventive on healthy Piro- 



ones. These did not meet with success, but were found to have a bearing as regards plasmosis— 

 rinderpest prevention. One cannot give further details here. 



Bugge-* mentions fairly good results obtained in the protective inoculation of cattle 

 against redwater by the injection of sterile, defibrinated blood from calves which have 

 recovered from the disease at least fifty days. These inoculations should be carried out 

 from four to six weeks before the animals are sent to grass. The precautions to be taken are 

 described. 



The occurrence of piroplasmosis in the goats of Central Africa is signalised by 

 Panse.3* The forms seen recalled P. parvuin of cattle. Piroplasmata have also been found 

 in sheep and in deer. 



Canine Piroplasmosis. A great deal of experimental work on this form has recently 

 accumulated. Thus wo have the important papers of Nuttall and Graham-Smith,* 

 who have studied the parasite as it is found in the peripheral blood, both in fresh and stained 

 films. Their work, which is profusely illustrated, led them to the following conclusions : — 



1. Nearly all forms of piroplasma show one densely staining mass of chromatin — the nucleus ; many also show 

 a second punctiform dense mass generally situated near the nucleus — the blepharoplast ; and a considerable 

 number show a third loose mass which has not been previously observed. These masses may occupy various 

 positions, or assume various shapes, the signiticance of which we have not yet been able to determine. 



2. Many intracorpuscular forms in stained preparations show both pseudopodia and flagella-like processes, 

 and many of the free forms possess distinct flagella. 



3. Round forms, apparently in a degenerating condition, are common in liver and spleen smears. In these 

 situations free masses of chromatin also occur, probably derived fi-om degenerated parasites. 



4. Many of the appearances seen in stained preparations are extremely deceptive, and deductions made fi'om 

 them are frequently not confirmed by the study of living forms. 



5. Various bodies occur in normal dog's blood, which may readily be mistaken for piroplasmata. 



6. Piroplnsma canis has a truly intracorpuscular and an extracorpuscular stage. In the former condition, 

 round, amoeboid and pyriforra bodies occur, all of which are to some extent motile, and in the latter, long and 

 pyriform, frequently flagellated free swimming bodies. Amoeboid extracorpuscular forms are never seen. 



7. Within the peripheral blood a definite cycle of development occurs. Free pyriform bodies invade the 

 corpuscles, become round and later amceboid. The amoeboid bodies, according to their size, either again form 

 intracorpuscular pyriform bodies or divide and form two or more pyriform bodies. The pyriform bodies leave the 

 corpuscles, and in doing so, rupture them and enter other corpuscles. 



A free pyriform parasite enters a normal red blood corpuscle and rapidly assumes a rounded form. It then 

 enlarges and passes through an actively amoeboid stage, at the end of which it again becomes rounded. After a 

 short period of quiescence in this condition it protrudes two symmetrical processes, which rapidly grow and 

 become pear-shaped. The protoplasm of the parasite flows into these processes, and its body consequently 

 gradually diminishes until it is represented by a minute rounded mass to which the pyriform processes are 

 attached. Eventually this also disappears, and finally two mature pyriform parasites are left, which are joined 

 together for a time by a thin strand of protoplasm. After a variable time these parasites are liberated by the 

 rupture of the corpuscle, and swim away to enter fresh corpuscles and repeat the process. 



Occasionally a single, rounded intracorpuscular parasite, by the protrusion of several processes such as have 

 just been described, gives rise to four or more mature parasites, or a single parasite divides into two small rounded 

 parasites, each of which produces two pyriform parasites. 



Under experimental conditions all parasites, which are liberated by the rupture of the corpuscles containing 

 them before they have reached the mature pyriform parasites which fail quickly to enter fresh corpuscles, 

 disintegrate and die. 



We have never observed any forms which could be regarded as gametes. 



Christophers''' monograph is not only an excellent dissertation on Piroplasma canis, but 

 contains a review of the whole subject of piroplasmosis and a consideration of the ticks 

 which attack dogs. One or two points dealt with in his review may be mentioned : — 



1. The blood of recovered animals is infective, even though parasites may not be demonstrable under the 

 microscope. 



' Theiler, A. (July, 1907), " Experiments with Serum against East Coast Fever." Journal of Tropical 

 Veterinary Science, Vol. II., No. 3. 



^ Bugge (March, 1908), "Protective Inoculation against Redwater in Cattle." Quoted in Journal of 

 Comparative Pathology and Therapeutics, Vol. XXI. 



= Panse (1908). Arch.fUr Schiffs. und Tropen. Hyy., Bd. XII. 



« Nuttall, Q. H. F., and Graham-Smith, Q. S. (July, 1905, October, 1906, April, 1907), "Canine Piroplas- 

 mosis." Journal of Hygiene, Vols. V., VI., VII. 



' Loc. cit. 



• Article not consulted in the original. 



