1912] . CURRENT LITERATURE 435 



part of the foliage of the host plant. The analysis is interesting, but incom- 

 plete. The lengthy and well selected bibliography will be valuable for workers 

 in biochemistry. 



A paper by Houard 16 is subdivided into five parts as follows: (i) table of 

 galls previously described, in which are listed 26 species with bibliography of 

 each and grouped with reference to the host plants; (2) new observations upon 

 the new galls of Tunis, in which the author gives brief discussions of 93 cecidia, 

 some of which are assigned to genera only; these cecidia are also grouped with 

 reference to the host plants; most of them are attributed to insects, one on 

 Moriandia cinerea Cosson is caused by Cystopus candidus, one on Oka europaea 

 L. is caused by Bacillus oka (Arc.) Trev., and a third is referred to as a fas- 

 ciation without comment as to cause; (3) a very valuable bibliography on 

 the zoocecidia of Tunis from 1894 to date; (4) a table of galls arranged with 

 reference to host plants; (5) a table arranged with reference to the organisms 

 causing the galls. 



Costerus and Smith 17 have represented a very interesting paper on tropi- 

 cal teratology. Malformations of 18 species (7 of which belong to the family 

 Orchidaceae) are carefully described. These descriptions are far better than 

 those frequently given in papers on teratology in that the relationships of the 

 parts have been carefully worked out. No explanation is offered as to the 

 cause of these peculiar structures. — Mel T. Cook. 



Gas movements in plants. — It is a question of some interest whether 

 static diffusion accounts for essentially all the gas exchanges of foliar inter- 

 cellular systems or whether molar movement is also considerably involved. 

 Ohno 18 has already shown how "hygro-diffusion" leads to such a molar extru- 

 sion of gas in the leaf of N dumbo nucifera, and has explained the physics of 

 the action. Now Ursprung 19 shows that the same process plays an important 

 part in the gas movements in the leaves of Nymphaea and Nuphar. The first 

 half of the article is devoted to a critical historical review of the work on 

 Nelumbo. The conclusions reached agree with Ohno in all essential points, 

 although that author has given the earlier literature a less critical considera- 

 tion than is desirable. As Ursprung states, it has generally been believed 

 that the observed gas exchanges and positive and negative pressures in the 

 intercellular systems of Nymphaea and Nuphar are entirely determined by 

 photosynthetic and respiratory activities. A mention of two of his experiments 

 will show clearly that "hygro-diffusion" plays an important role in these forms. 



Houard 



Smith 



Marcellia 10:160-184. 1912. 

 tropical teratology. Ann. Jard. 



Bot Buitenzorg II. 9:98-116. pis. 5. 191 1. 

 i8 Bot. Gaz. 51:310. 191 1. 



19 Ursprung, A., Zur Kenntnis der ( 

 156. 1912. 



Flora 104:129- 



