ZOOLOGY AND BOTANY, MIGEOSCOPY, ETC. 399 



the Puccinia is very common in districts where the barberiy is un- 

 known, and according to De Bary the Puccinia spores cannot be made 

 to germinate and grow upon grasses. Mr. Plowright, however, was 

 able in a limited number of cases to make the Puccinia spores grow 

 upon wheat, especially on young seedlings. 



Infectivity of the Blood.* — G. F. Dowdeswell discusses the in- 

 fectivity of the blood and other fluids in some forms of septic disease, 

 and the reputed occurrence therein of an increase of virulence in 

 successive inoculations, and he comes to the conclusion that in the 

 cases in which he has experimented, Davaine's septicbfemia in the 

 rabbit and the so-termed Pasteur's septichsemia in the guinea-pig, 

 there is no increase of infective virulence in the septic fluids in suc- 

 cessive generations, either in respect to the minimal quantities required 

 in the incubation period, nor as to any constant difference in the 

 length of the incubation period. Inflammatory products are more 

 variable, and this is probably partly due to differences in the severity 

 of the cases affording the infective matter (Burdon-Sanderson), and 

 partly, as the author states, to constitutional idiosyncrasy in the 

 animal inoculated. In Davaine's septichtemia there can be little 

 doubt but that the microphyte constitutes the actual contagium, but 

 in Pasteur's septichsemia the microphyte is not simply or per se the 

 contagium, though, no doubt, it may modify the pathological con- 

 ditions. The author states that he has relied greatly on the Micro- 

 scope, and he looks to the use of its greatly increased powers for the 

 advancement of our knowledge of this subject. 



New Species of Micrococcus.f— T. J. Burrill describes M. amy- 

 livorus, found in the tissues of plants, and causing the so-called 

 "fire-blight." By the action of this organism the stored starch is 

 destroyed by fermentation, and carbonic acid, butyric acid, and 

 hydrogen given off. It may be cultivated in pure starch in water at 

 a moderately warm temperature. M. toxicatus is found in species of 

 Bhus, and is believed to be the peculiar "poison" for which these 

 plants are known. If transferred to the human skin they multiply 

 rapidly, penetrate the epidermis, and give rise to inflammation. 

 M. insectorum has been found in the digestive organs of Blissus leu- 

 cojpterus ; the insect may be sometimes observed to die off in great 

 numbers, and to present every appearance of suffering from a conta- 

 gious disease, of which these organisms are no doubt the true element. 

 The name of M. gallicidus is given to the organism which appears in 

 the blood of the domestic fowl when suffering from " chicken cholera," 

 and which, though often described, does not seem to have been ever 

 named. Similarly the name of M. suis is given to the form which 

 appears to be the dangerous element in " hog cholera." 



Influence of Light on the Development of Bacteria.^ — In con- 

 nection with the sanitary state of the hospital at Melbourne, J. Jamieson 

 has carried out a series of experiments on this subject. He inoculated 



* Proc. Eoy. Soc, xxxiv. (1883) pp. 449-69. 

 t Amer. Nat., xvii. (1883) pp. 319-20. 

 J Proc. Roy. Soc. Victoria, June 8, 1882, 



