286 SUMMARY OF CURRENT RESEAHOHES RELATING TO 



into the adult cell, which attains a height of from 90-170 fx. C. pohjrliizum 

 is found on empty marine shells, which also serve to support Masligocoleus 

 testarum* 



Urococcus, Coccochloris, and Polycystis.f — Herr P. Eichter describes 

 the life-history of Urococcus insignis. In its early stage it has all the 

 appearance of a Gloeocystis, but is not identical with any known species. 

 The well-known " stalk " is not peculiar to the genus, but belongs also to 

 Gloeocystis and Hormotila. When actively growing H. insignis has no 

 stalk, and is then simply inclosed in a larger or smaller number of ex- 

 centric envelopes, and closely resembles Chroococcus macrococcus, with 

 which it may be identical. 



The author proposes to restore the old genus Coccochloris, which has 

 been merged in Ajyhanothece, and describes C. stagnina Spreng., with which 

 he unites Aplianothece cserulescens Br. 



A remarkable new species, Polycystis scripta, is described, forming a 

 suljihur-yellow scum on the surface of salt water ; it appears to derive its 

 sustenance from decaying seaweeds. 



Pathogenic Bacteria.^ — Herr H. Mittenzweig summarizes the work of 

 German investigators on pathogenic bacteria. He adopts the classification 

 of Koch and Huppe, founded on their form. After describing the various 

 processes of studying bacteria, he details the observations of German bac- 

 teriologists on certain special microbes, such as those of cholera, typhoid 

 fever, gonorrhoea, syphilis, &c., the various properties of these bacteria 

 being described in detail. 



Tuberculosis of the 01ive.§— M. L. Savastano has investigated the 

 diseases of the olive somewhat indiscriminately known as " maladie de la 

 loupe " and '' rogna " ; some being caused by hypertrophy of the tissues 

 due to external causes, others by a special bacterium which forms tubercles 

 on the young branches. This bacterium, named by Arcangeli Bacterium 

 olese, was cultivated on potato and gelatin, but no exact description is given 

 of it. 



Tubercle Bacilli |1 — As the result of prolonged investigations, Herr 

 V. Sehron notes : — (1) the tubercle bacillus is in its young stage a torula- 

 chaiu ; (2) with increased growth the granular elements of the chain become 

 distant, and are united by a band ; (3) the intercellular substance of the 

 Bacillus is a secretion of these elements, and is formed by apposition ; 

 (4) in retrogressive metamorphosis the granules of the torula-chain become 

 free as bacillar spores ; (5) these liberated spores grow into mother-spores, 

 which exhibit a capsule and enclosed contents ; (6) the finely granular 

 contents of the mother-spores become daughter-spores ; (7) the daughter- 

 spores burst the capsules and issue singly or in a torula-chain (young 

 Bacillus) from the mother-spore. 



* See this Journal, 1886, p. G6.'). f Hedwigia, xxv. (1886) pp. 249-55. 



X Mittenzweig, H., ' Bacterien-Aetiologie der Inf'ections-Krankheiteu,' 136 pp., 

 Berlin, 1886. See Bull. Soc. Bot. France, viii. (1886), Rev. Bibl., p. 177. 



§ Comptes Kendus, oiii. (1886) pp. 1144-7. 



II Ber. .59 Veraamml. Deutsch. Naturf. u. Aerzte, Berlin, 1886. Cf. Biol. Centralbl., 

 vi. (1886) p. 634. 



