264 EECOKD OF CUERENT RESEARCHES RELATING TO 



presence of tentacular organs in forms living in running water is 

 regarded as an indubitable advantage, inasmucli as these parts are 

 extremely sensitive, and it may well be said that the service they 

 render is in direct relation to their length. The author is, further, of 

 oj)inion that the food of these creatures is a factor in their protective 

 arrangements, by exerting a direct influence on the colours of their 

 integument, and he illustrates this by the case of D. lacteum which he 

 fed largely on the larvse of Ghironomus, and in which he found that the 

 gastric diverticula became red, and that this tint extended in time to 

 the reticular tissiie of the body. So too there is the case of Dijiojihilus 

 vorticoides, which is coloured a bright red, but in which the colour is 

 not regularly distributed, but is found best marked in the greatly 

 sacculated stomach ; this may be easily explained by a reference to 

 the food of these creatures, which consists largely of diatoms and of 

 the debris of red algaa. 



Land Planarians of Germany.* — Dr. Kennel, after paying a 

 well-deserved tribute to the labours of Mr. Moseley, discusses the 

 grounds on which Bhynchodesmus terrestris 0. F. M. and Geodesmus 

 bilineatus Metschnikoif are regarded as part of the fauna of Germany. 

 No one can have much doubt as to the habitat of the first, but it is 

 possible that some naturalists would hesitate more than does our 

 author in regarding the second as indigenous to Germany. These 

 creatures appear to subsist on animal food principally. The author 

 deals chiefly with anatomical details, inasmuch as Moseley's histo- 

 logical results are so complete ; with regard, however, to the cilia 

 with which these animals are ordinarily considered to be covered, 

 he points out that Moseley's result in which sections only revealed 

 cilia on the ventral surface, can be paralleled by other members of 

 the same group in which cilia are most certainly distributed over the 

 whole surface of the body ; and he supposes that at death the strongly 

 developed rods in these creatures, obscure the discrimination of the 

 cilia. The epidermis on the ventral surface is different in character 

 to that found in other parts, for it consists of regular low cylindrical 

 cells between which there are no unicellular glands nor any rods ; 

 on either side of this ventral portion (Sohle), the epidermis becomes 

 much thicker and consists apparently, in well-developed animals, of 

 almost only rods ; true ciliated cells may, however, be made out in 

 thin sections from which the rods have dropped away. The struc- 

 tures which Mr. Moseley took for unicellular glands are regarded as 

 being rather rods which have been altered in character by the use of 

 reagents. 



The musculature is best developed on the ventral surface, where 

 it is separated into several distinct layers; like Mr. Minot, the author 

 was unable to discover any circularly disposed fibres. He looks upon 

 the inner layer of longitudinal muscles of the dorsal surface as 

 dividing into two layers on the ventral, and as having the nerve-fibres 

 between them. The digestive organs resemble in character the same 

 parts in the fi'csh- water Planaria, and Kennel would not, he says, enter 



* ' Arbeit. Zool.-Zoot. lust. Wiiizburg,' v. (1879) p. 120. 



