VETERINAKY SCIENCE AND PRACTICE. 991 



of sucli diseases mention niaj' be made of glanders, rabies, anthrax, tu])errnlosis, 

 milk sickness, smalliiox, diphtheria, searlet fever, and plague. Especial attention is 

 devoted to a discussion of the problem of tuberculosis and the value of the tuben'ulin 

 test in detecting the presence of incipient cases of this disease. 



Insects as a living medium for cultivating- infectious diseases of man and 

 animals, ('. vox Ihu.ni (('ndhl. llald.-n. Par., 1. Aht.,,:o (inOI), Xn.7 , pi>. ..'S4-2S7).— 

 The author conducted experiments in cultivating the organisms of ulcus molle and 

 syphilis in a large variety of living insects, including nearly all the orders of insects. 

 It was found that the organisms grew rapidly and luxuriantly in the body cavity 

 and various organs of all insects with which experiments were made. A rapid 

 growth and development of the organisms took place, whether the insects were 

 inoculated with the hypodermic needle or by being allowed to feed upon the organ- 

 isms. It was found that l)y infecting an insect and then i>lacing it in a cage with 

 other insects of the same or different species, all the other insects ultimately became 

 infected with the pathogenic organisms. The author calls attention to the great 

 importance of these facts for the future development of the bacteriology of infectious 

 diseases. 



Influence of the body cavity on the haemolytic po-wer of serum from other 

 animals, S. J. Meltzer (Cf»7W. BaU. u. Par., 1. AbL, 30 {1901), Xo.7, pp. 278-281).— 

 Numerous experiments in connection with this problem Avere carried out by the 

 author. It was found that the serum of cattle operated vigorously in disintegrating 

 the red blood corpuscles of rabbits. When the serum was previously kept for from 

 10 to 14 days at a temperature of living rooms, it was found that its hfcmolytic 

 property was entirely lost. Fresh normal serum of cattle maintained for 3 hours 

 in the body cavity of a rabbit loses almost entirely its power of dissolving the red 

 blood corpuscles of rabbits. During the experiment it was found that the serum of 

 cattle when placed in the body cavity of a dead animal soon lost its hssmolytic prop- 

 erty. It is concluded from these experiments that immune as well as normal sera 

 lose their haemolytic power by remaining for different lengths of time in the body 

 cavity of another animal. It is believed that the disappearance of this property of 

 the serum may be due to alexins. 



Involution forms of bacteria on salt-agar, which resemble the plague 

 bacillus, A. Rosexfeld (CmihL Bakt. ». Par., 1. Aht., 30 {1901), No. 17, pp. 641- 

 653). — The author investigated these forms in a number of bacteria, including the 

 bacillus of mouse typhus, of hog cholera, swine plague, ferret plague, chicken cholera, 

 pseudo-tuberculosis, and the bacillus of Danysz. The various bacteria were culti- 

 vated for a considerable time on artificial nutrient media, at a temperature of 37° C. 

 The usual formula was adopted for making a slightly alkaline agar mediuui, but 

 instead of adding only 5 gm. of sodium chlorid to the liter of bouillon, from 20 to 50 

 gm. were used. The growth of diffei-ent bacilli under these conditions showed great 

 differences. In general there was a noticeable check to the development of bacteria 

 in the presence of a large percentage of salt. The organisms of swine plague, pseudo- 

 tuberculosis, and chicken cholera produced only a weak growth, even m the pres- 

 ence of slight quantities of salt, while the organisms of hog cholera, mouse typhus, 

 and ferret typhus showed quite vigorous development in the medium containiug5 per 

 cent of salt. In connection with the decrease in growth a modilication of the form 

 of individual elements was noted. In the organisms of hog cholera, ferret plague, 

 and mouse typhus this phenomenon was first observed in media with a high salt 

 content, and consisted simply in an enlargement of the rods and the formation of 

 threads with considerable branching. In cultures of the bacillus of Danysz in media 

 containing 5 per cent of salt, many swollen forms were observed, club-shaped, 

 spindle-shaped, or even spherical. The vai-ious modifications of form which occurred 

 under the influence of different percentages of salt in the nutrient media are described 

 in detail. The author maintains, however, that these involution forma produced 

 under the influence of salt should not lie mistaken for the plague bacillus. 



