88 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The disappearance of the tadpole’s tail has been described by 
M. E. Metschnikoff as being the result of a “ muscular phagocytosis,” a 
condition in which the whole of the muscle becomes converted into a 
mass of phagocytes, inclosing within them the striated substance of the 
muscles ; these phagocytes are therefore developed from the muscle 
itself, and are not connected with leucocytes at all. In the formation of 
the muscular phagocyte the sarcoplasm and nuclei of the fibril partici- 
pate, the myoplasm — i. e. the sarcolytes — being destroyed within them. 
Eventually these phagocytes appear in the abdominal cavity as lymph- 
leucocytes. 
According to Dr. A. Looss, the degeneration is carried out through 
the agency of the lymph ; according to M. E. Metschnikoff, it is self- 
begotten of the muscle-fibril. 
In his reply, Prof. E. Metschnikoff * makes his position quite clear as 
to the cause of the atrophy of the tadpole’s tail. It is the result of 
phagocytosis, an active process, and not, as Dr. Looss considers, due to 
absorption of the muscular tissue by the fluids of the body. Moreover, 
the two observers seem to be at variance as to their facts, for according 
to Metschnikoff, the striated muscular substance only disappears, while 
Looss contends that the whole fibril is absorbed. It is, therefore, no 
wonder that considerable scientific recrimination takes place, and though 
Prof. E. Metschnikoff’s facts seem indubitable — for, as he says, well- 
known savants such as Malassez have admitted their correctness — yet 
his adversary is clearly his superior in polemical writing — e. g. it is not 
argument to say that certain illustrations show no nuclei, and yet they 
were undoubtedly present — that is merely another way of saying that a 
scientific opponent has, well, suppressed certain facts, and is not fit for 
ordinary society. 
Spleen and Immunization.! — Dr. A. A. Kanthack, after noting the 
results of Tizzoni and Cattani, who showed that it is impossible under 
certain circumstances to render rabbits from which the spleen had been 
removed immune to tetanus, remarks that tetanus is, par excellence , an 
intoxication disease, and that it would be illogical to draw general 
inferences therefrom. It is important, therefore, to ascertain the beha- 
viour of animals without spleens towards other microbes, the virulence 
of which depends in a less degree on intoxication. The infection of 
Bacillus pyocyaneus was chosen, and its action observed (1) on rabbits 
from which the spleen bad been removed, and then treated in company 
with other fresh animals by various methods of immunization ; (2) on 
rabbits which had been rendered immune, and then deprived of their 
spleen. The experiments showed that in Pyocyaneus infection, absence 
of the spleen exerted no influence whatever. 
Bacteriological Examination of Water.| — One of the principal objects 
of Herr Max Dahmen’s investigation was to ascertain the optimum 
amount of sodium carbonate which should be added to meat-pepton- 
gelatin in order to bring about the development of the greatest number 
* Centralbl. f. Bakteriol. u. Parasitenk., xii. (1892) pp. 294-6. 
t Tom. cit., pp. 227-9. 
X Chemiker-Zeitung, xvi. (1892) No. 49. See Centralbl f. Bakteriol. u. Parasi- 
tenk., xii. (1892) pp. 302-3. 
