ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 7 'J 5 



Micro-organism found in the mucous flux of Trees.* — In 1886 Prof. 

 Lndwig described an alcoholic fermentation and mucilage which he had 

 observed in certain trees, and expressed the opinion that the fermenta- 

 tion was due to a fungus which he called Endomyces Magnusii. Besides 

 this, two other Saccharomycetes and a new ScLizomycete, Leuconostoc 

 Lagerheiinii, were noted. From further observations, published in 1888, 

 Prof. Ludwig concluded that the mucilage was due to Bacteria. 



Dr. E. C. Hansen now describes the mucilage which he has observed 

 in seventeen cases, and in only one of these was the Endomyces Magnusii 

 found ; hence this author points out that it cannot be considered the 

 cause of the flux. Owing to the number of different animal and 

 vegetable parasites in these seventeen cases, Hansen concludes that it 

 woulil not be safe to infer that any one was the specific cause of the 

 mucilage, but is of opinion that, considering the cause of " pear-blight" 

 has been shown to be a bacterium, the Micrococcus amylovorus, it is 

 probable that a bacterium should be sought for as the cause. 



He then goes on to discuss one of the Saccharomycetes found by 

 Ludwig in the scum on the trees. The latter considered this Saccharo- 

 myces to be a developmental stage of Endomyces and its Oidium. The 

 question Hansen resolves into : — Can the Oidium-form. be made to 

 develope into the E7ido7nyces-iorm? can the Saccharomyces be developed 

 from the Oidium, and conversely, if starting from the Saccharomyces, 

 can the Oidium and Endomyces be obtained? These questions are 

 answered in the negative. 



Still more recently, Prof. F. Ludwig f has made further contributions 

 to the pathogenesis of this disorder, and he states that the mucous flux 

 is produced by the symbiotic schizomycete, Leuconostoc Lagerheimii. 



Considering, however, the number of micro-organisms and their 

 great differences, the question would not ajjpear to be at present 

 answered satisfactorily. 



Pleomorphism of Bacteria.^— M. Metschnikoff replies in an article 

 on the pleomorphism of Bacteria to the theories enunciated by Wino- 

 gradsky. 



Spirohacillus Cienkowslci, which was made the subject of examination, 

 justifies its name, as it passes successively through the stages of Bac- 

 terium, Bacillus, and Spirillum. This parasite attacks the small aquatic 

 crustacean Baplinia, and imparts to it its red colour. 



The author was able to follow the transformation of the Bacteria 

 through the different phases of the disease : the stages figured seem to 

 form tiie transition between the most distant forms. The author's results 

 were, however, not obtained by cultivations, consequently they are not 

 altogether convincing. 



Movements of Micrococci.§ — It is usually accepted, says Dr. C. H. 

 Ali-Cuhen, that micrococci are not endowed with any characteristic 

 movements. There are, however, no a priori considerations why this 

 kind of Bacteria should differ from other kinds ; that is, why a spheroidal 

 microbe should be iucapable of motion, while an oval or rod-like one 

 should be gifted with specific movements. 



* Centralbl. f. Baktoriol. u. Parasitenk., v. (1889) pp. 632-40, 663-67, 693-6. 

 Cf. this Journal, 1887. p. 285. t 'J'- o., vi. (188'J) pp. 13M-7, 162-5. 



X Ann. Inst. I'asteur, 1889. Cf Bull. Soc. Bot. France, xxxvi. (1889) p. 51. 

 § Centralbl. f. Bakteriol. u. Parasittnk., vi. (1889) pp. 33-6. 



