ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 321 



means for distributing the seed, such as washing away by water or 

 transportation by wind or animals. 



Triadenum virginicum, Rafinesque.* — T. Holm adduces evidence 

 based on morphological and anatomical characters in support of Ra- 

 finesq ue's view of the generic distinction of Linnasus's Hypericum 

 virginicum. Rafinesque separated his genus from Hypericum solely on 

 the floral glands and reddish flowers, but a study of the plant from the 

 seedling and of the subterranean organs in connection with an ana- 

 tomical investigation of the vegetative organs compared with those of 

 other species of Hypericum, has convinced the writer that Triadenum 

 shows sufficient morphological and anatomical characters to entitle it to 

 generic distinction. Its more or less tuberous stolons with scale-like 

 leaves, are not met with among the species of Hypericum proper ; and 

 the subterranean organs offer several points of interest in which the 

 proposed genus shows a marked deviation from Hypericum. The vena- 

 tion of the leaves is also peculiar and characteristic ; the veins are very 

 prominent on the lower face of the blade, and the secondaries are more 

 numerous but shorter, and proceeding from the mid-rib under an angle 

 that is much broader than is observable in the leaves of Hypericum. 

 In the latter the secondaries proceed, as a rule, from below the middle 

 of the mid-rib, while in Triadenum they are noticeable almost to the 

 apex of the blade. 



The author gives a somewhat detailed account of the anatomy of 

 the vegetative organs, and points out certain differencies as compared 

 with species of Hypericum. The disposition of the ducts seems cha- 

 racteristic of the genus Triadenum as compared with the other 

 Hypericaceas. 



Hairs of Aquatic Plants, f — E. Barsali discusses the significance 

 of the hairs of aquatic plants. He cites on the one hand the opinions 

 of Stahl and Schrenk, that muciparous hairs protect the young organs 

 from the attacks of animals, and of colonies of alga3 and bacteria ; 

 and on the other hand the opinions of Goebel and Schilling, that these 

 hairs remove the young leaves from immediate contact with water. 

 From his own researches, he comes to the conclusion that the sole 

 object of the hairs, whether muciparous or not, is to protect and defend 

 the young organs from external influences. 



Development of Stamens in the Interior of the Ovary of Melan- 

 dryum.J — F. Buchenau describes some abnormal flowers of Melandryum 

 rubrum found near Marburg, which at first sight appeared to be 

 apetalous female flowers. Examination showed them to consist of a 

 single whorl of rive leaves, which showed in a manner varying con- 

 siderably in different specimens the character partly of sepals and partly 

 of carpels. The members were united to form a chamber more or less 

 open at the top ; from the lower part of the chamber sprang a whorl 

 of stamens of normal form, generally six to nine in number, sometimes 

 ten. On one occasion a row of ovules was found on the united edges 



* Anicr. Journ. Sci., xvi. (1903) pp. 369-7G (figs, in text). 



t Bull. Soc. Bot. Ital., 1903, pp. 301-7. 



X Ber. Deutsch. Bot. Gesell. xxi. (1903) pp. 417-24 (1 pi.). 



