ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 461 



Dendroceros), and the water-retaining outgrowths of A. arachnoideus. 

 The author points out the frequency of similar structures in parallel 

 groups of the hepatics, citing such instances as leaf-formation, water- 

 sacs, paraphyllia, mucous papilla?, premature spore-germination, etc. 



Moss Rhizoids.* — K. Schoene discusses the germination of moss- 

 spores and the biology of moss-rhizoids, with special reference to the 

 rhizoids of the protonema, prefacing his paper with a summary of 

 previous work on the subject. He gives the results he obtained by the 

 culture of spores and protonemata on various nutritive solutions, em- 

 ploying some eight of the commonest species. By the omission of 

 nitrates and phosphate he obtained in both cases a profuse growth of 

 rhizoids of Funaria hygrometrica, and no, or very little, chloronema 

 respectively. The other mosses behave quite differently, producing 

 growths that contain no chlorophyll, and correspond with neither rhizoid 

 nor protonema. The author treats also of the form, meaning, and 

 function, of the rhizoids, and of the obliquity of the transverse walls, 

 and of the mechanical advantage they confer upon the plant. 



Moss Gralls.j — V. Schiffner continues his studies begun last year on 

 moss galls. He has found them occurring on 27 species, including both 

 acrocarpous and pleurocarpous, but never on any species of liverwort. 

 All the instances recorded occur on European specimens. The galls are 

 caused by the attack of a Nematode worm, Tylenchus Davainii Bast., 

 and though they are formed on such different species of mosses, they all 

 show the same structure and occur in the same position — namely, at the 

 growing point of a vegetative shoot. They are in the form of bulbous 

 buds, and show, in the cell structure of the enveloping leaves, much 

 similarity with the male buds of the respective species. The galls are 

 almost without exception entirely independent of the inflorescences. As 

 a rule, the growing point is destroyed by the gall, but the author records 

 an instance in which the shoot continued growing through the gall 

 structure ; the species in question was Dkranum longifolium. Fungal 

 hyphas and rotatoria are found in the galls sometimes as well as the 

 Nematodes, but the author regards these as being chance visitors. There 

 is no symbiosis between the moss and the Nematode, nor is it a case of 

 true parasitism, but merely what the author terms " room-parasitism." 

 At the same time there is distinct injury done to the host, which never 

 fruits, but becomes bushy in a manner reminding one of the witches' 

 broom of higher plants. 



Abnormal Moss-Capsules. J — W. Monkeineyer describes abnormal 

 specimens of Dicranella varia and Bryum saxonicum Hagen, in which 

 the capsule shows two, sometimes three, lids divided from one another 

 by a hollow cylinder. There is also a multiplication of peristomes, one 

 on the margin of the theca growing upwards in a normal manner, while 

 the other is inserted on the margin of the lid and grows downwards. 

 Many of the teeth of one peristome had united Avith the teeth of the 



* Flora, xcvi. (1906) pp. 276-321 (figs.). 



t Hedwigia, xlv. (1906) pp. 159-72. 



t Tom. cit., pp. 178-81 (2 pis., 6 figs, in text). 



