ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 79 



Development of Hypholoma.*— Caroline L, Allen publishes the 

 results of her examination of several species of Hypholoma. The method 

 of growth was so similar in all that they might have ranked as one 

 species. She sums up thus : — (1) The hymenium of HtjphoUma 

 suUateritium and allied forms is endogenous in its origin. (2) A 

 universal veil (primordial cuticle) is present from the beginning. (8) 

 Pileus, hymenium, lamellae, and upper portion of the stipe are formed 

 by the growth and differentiation of a small central area of tissue. (4) 

 The gill cavity is formed internally after the formation of the hymenial 

 primordium by breaking of the hyph^e beneath this. (5) The lamellae 

 are formed by the unequal growth of the hyphae of the hymenial 

 primordium. (6) In one species, the cystidia appear at a very early 

 stage and soon attain their highest development, being much more 

 prominent then, than in the mature plant. Differentiation of tissue 

 begins when the plant is about 1 mm. high, and reaches an advanced 

 stage before it is 5 mm. high. 



Development of Agaricus campestris.t — ^Gr. F. Atkinson has brought 

 together the studies and theories of many workers as to the growth of 

 the fruit-body of the mushroom and allied fungi, and he adds the results 

 of his own observations. He notes first the primordium of the carpo- 

 phore, a homogeneous body composed of slender, uniform, dense hyphae 

 surrounded by an outer layer, the universal veil. The formation of the 

 hymenium, which is endogenous in its origin, is followed in detail and 

 the differentiation of stipe and pileus. In cultivated forms the basidium 

 bears two spores only, the wild plants have four spores. 



Question of Species in Parasitic Fungi. J — Ed. Fischer explains the 

 existence of biological and physiological species so often found among 

 the Uredineae and discusses their position in any practical system of 

 classification. He concludes that those forms which constantly show 

 morphological differences must rank as species. Other forms which 

 differ from each other only slightly should be united in collective species, 

 and those biologically different should rank as sub-species. 



Plant Diseases. — J. B. S. Norton § gives descriptions of various 

 fungoid diseases that attack potatoes, with the treatment necessary in 

 each case. The chief of those mentioned are caused by Oospora scabies, 

 Rhizoctoida, Fusarium oxysjyorium, Bacillus solanacearum, Alternaria 

 Solani, and Phytophthora infestafis. 



The ripe rot or Mummy Disease of guavas has been studied by 

 J. L. Sheldon || who finds that it is caused by Gloaosporium Psidii with a 

 perfect fruiting stage belonging to the genus Glomerella. He describes 

 the development of the fungus. 



H. FassilF describes a new species of Leptosphferia which he found 



* Ann. Mycol., v. (1906) pp. 387-94 (3 pis.). 



t Bot. Gazette, xlii. (1906) pp. 241-64 (6 pis.). 



i Ver. Schweiz. Nat. Gas. Luzern, Ixxxviii. (1906) pp. 300-8 (6 figs.). 



§ Maryland Agric. Exper. Stat. Bull., cviii. (1906) pp. 63-72 (4 figs.). See 

 also Bot. Centralbl., cii. (1906) p. 497. 



II West Virginia Agric. Exper. Stat. Bull., civ. (1906) pp. 299-315 (4 pis., 29 figs.). 

 See also Bot. Centralbl., cii. (1906) p. 498. 



^ Bull. Lab. ed Orto Bol. Siena, vii. (1905) pp. 57-62 (1 pi.). Seo also Bot. 

 Centralbl., cii. (1906) p. 471. 



