902 SUMMARY OF CURRENT RESEARCHES RELATING TO 



which reproduces its species in water containing |^th of urine better 

 than in water devoid of salts. It can be reconciled to a strongly 

 saline solution, so that in five weeks it multiplies with great rapidity 

 in unmixed blood. The author ascribes the acquisition by Infusoria 

 of the power of existing in the body to the habituation to the saline 

 contents rather than, as Grawitz holds, to the alkaline principles 

 there found. 



Dr. Koser has also demonstrated to his own satisfaction that vege- 

 table seeds (peas and beans) when placed in urine or hydrocele fluid 

 swell up, but do not germinate ; from this he concludes that the 

 reason why seeds which penetrate into the air passages, the nostrils, 

 or auditory meatus fail to germinate in spite of the favourable con- 

 ditions of moisture, warmth, and carbonic acid which they meet with, 

 is that they, or rather the plants which produced them, are not 

 accustomed to the amount of salts contained in the blood. The 

 leading principle laid down is that " no parasites or infectious fungi 

 are able to gain a footing in the animal body, but such as have been 

 previously adapted to the proportion of saline matter in the blood. A 

 cell of necessity collapses when transferred from a medium which is 

 poor in salts, such as good drinking water, directly into the serum of 

 blood. Drinking water rich in salts is bad, i. e. likely to convey 

 infection." If this is true, the first thing required for successful 

 inoculation or infection with such organisms is that they shall not 

 be found to assume, by abstraction of water, the dried-up condition 

 on being transferred to a new medium containing salts. 



Infusoria Parasitic in Cephalopods.* — Alex. Foettinger found 

 in the renal organs of Sepia elegans and Octopus vulgaris two Holo- 

 trichous Infusoria, for which he proposes the names of Benedenia 

 elegans and B. coronata. In other Cephalopods which he examined 

 he found no parasites but Dicyema in those organs. B. elegans is 

 elongated and cylindrical, but enlarged at its anterior extremity ; at 

 the anterior end of the head there is sometimes seen an apparent 

 solution of continuity which may perhaps be a cytostome. In length 

 the creatures may attain to 1 mm. ; their mode of movement is 

 somewhat peculiar, for in addition to moving forwards they are 

 rotated on their own axis ; sometimes the body is folded at certain 

 points, but the animal may move without these folds disappearing. 

 These movements are due to the vibratile cilia which cover the whole 

 of the body, or to muscular fibrillfe, which in the living state have an 

 elongated S-shape, and give rise to the appearance of fine transverse 

 striae. The fibrils extend from the anterior to the posterior end, and 

 form a spiral around the body. There is no sign of any digestive 

 tube or anus ; the vacuoles are not contractile, the nuclei are invisible 

 during life and are only seen when the Infusorian is treated with 

 colouring matters. In some cases there is a single ribbon-shaped 

 nucleus which extends throughout the whole length of the body ; 

 sometimes there are a small number of ribbon-like bodies, which give 



* Bull. Acarl. R. Belg., 1. (1881) pp. 887-95. Arch, de Biol. ii. (1881) 

 pp. 345-78 (4 pis.). 



