ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
225 
white scum. The second was found in the blood of a cow which was 
supposed to have died of anthrax. The coarse appearances of the culti- 
vation were similar to those of B. leptosporus. These two bacteria are 
designated hay-fungi, not only from the resemblance of the scum which 
they form on the surface of the nutrient media, but also from the habitual 
likeness which the individual elements and the chains of rodlets show to 
those of B. suhtilis. 
B. leptosporus receives its name specially from the length of the 
rectangular endospores, and B. sessilis from the fact that one end of the 
germinating primary element remains covered for a considerable time 
by the spore-membrane, and thus there is imparted to the development 
of the micro-organism a special characteristic hitherto not observed in 
any other species. 
These bacteria were found to thrive well in most solutions, but best 
in meat -extract to which grape-sugar was added. The observations were 
made in the usual w^ay from cultivations in hanging drops, and examined 
under high powers. The author gives minute details of his observations, 
and numerous illustrations of the micro-organism at various periods of 
development. 
Bacteria-destroying Power of the Blood.* — In experimenting on 
the property of blood-serum devoid of cells as to its power of destroying 
micro-organisms. Dr. F. Nissen used the blood of dogs and rabbits. 
The blood was withdrawn from the carotids and received into sterilized 
vessels heated up to 35° C., and then defibrinated with sand. In the 
result it was found that while the various kinds of bacteria did not 
behave in the same way, yet a great number were found to be quickly 
destroyed by the blood influence. Of the pathogenic species which were 
found to be susceptible to this blood power were the bacteria of cholera 
asiatica, anthrax, typhoid, and pneumonia, and of the Saprophytes, 
Coccus aquatilis, Bac. acidi lactici, suhtilis, Megatherium. On the other 
hand. Staphylococcus aureus, albus, Streptococcus erysipelatis, bacilli of 
fowl cholera, swine plague, Proteus vulgaris, hominis, B. fluorescens, 
prodigiosus, aquatilis, and others multij^lied with great facility. The 
power of killing bacteria possessed by the blood is also influenced by 
certain conditions and reagents ; thus, if heated for half an hour to 
54°-56° C. it loses it, as is also the case if allowed to stand for some 
hours, or if its coagulability be affected as by the intravenous injection 
of pepton, or by admixture with sulphate of magnesia. 
Moreover, the quantity of micro-organisms has great influence on the 
result, the annihilating influence of the blood being only able to prevail 
up to a certain extent ; when this point is reached, the blood becomes 
quite a perfectly suitable medium for their development. 
The author concludes from the foregoing experiments, and also from 
others made with horse’s blood, that the power of the blood to overcome 
bacteria is to be regarded as a destructive property residing in the 
plasma, but he does not exjdain if there be any reason to suppose that 
there exists a definite separable constituent of the plasma which is 
capable of producing this effect. 
* Zeitsclir. f. Hygiene, vi., Heft 3. Cf. Ceiitralbl. f. Bakteriol. u. Parasitenk., vii. 
(1890) pp. 36-8. 
1890. 
Q 
