730 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Lindner has taken up the question, and states that these flattened por- 

 tions do exist, but that vacuoles are also present in the cells.* The 

 subject is further discussed by Rommel, who supports Lindner as to 

 the existence of vacuoles. 



Fusion of Ustilaero Conidia.f — Harry Federley distinguished two 

 forms of conidia in Ustilago Tragopogi-pratensis. In one form each pro- 

 mvcelium formed one conidium. As soon as the conidia were free they 

 congregated in pairs and then formed a long germinating filament. 

 Germination took place only in water ; any addition of nutritive substance 

 killed the conidia. In the other form numerous conidia were produced 

 both in water and in nutritive media, but no copulation took place. A 

 careful examination of the fused conidia showed that the nucleus from 

 one conidium passed over and fused with that of the other conidium ; 

 after germination had begun the protoplasm of the conidium also passed 

 over. Federley thinks that the fusion of the nuclei points to sexuality, 

 though it is difficult to arrive at a decision. 



Infection of Cereals by Smut Spores. J — Ludwig Hecke has proved 

 conclusively that there are two methods of infection of cereals by Ustilago. 

 There is the attack of the seedling plant, and there is a more insidious 

 infection of the seed in an early stage of development. Hecke watered 

 developing flowers of barley with smut spores while the stigma was still 

 quite fresh. When the seeds were developed he freed them from chaff, 

 thoroughly sterilised the outer coats and left them to germinate for a 

 while in sterilised conditions. Examination of the growing embryo 

 proved the presence in the cells of healthy mycelium, which he concluded 

 had been produced by the smut spores with which he had watered the 

 flower. Further research is promised. 



Deformation caused by an J5cidium.§ — C. Massalongo describes 

 the effect produced by JEcidium Euphorbim on the young shoots of 

 Euphorbia Cyparissias, of which the roots and underground stem were 

 invaded by the mycelium of the fungus. He gives an account of four 

 different plants affected by the fungus. The shoot, the leaves, and the 

 flower were all dwarfed or altered in growth : usually the shoots were 

 sterile and the leaves hypertrophied and covered with the fructifications 

 of the JEcidium. 



Uredinese.|| — Ed. Fischer brings to a close the account of his culture 

 experiments with rust fungi. Uromyces solidaginensis, he finds, possesses 

 only teleutospores. The JEcidium, on Linosyris vulgaris, is connected 

 with a Puccinia, on Carex humilis. A Melampsora that occurs on Larix 

 decidua and Salix retusa grows abundantly on the latter and on Salix 

 herbacea, less freely or not at all on other species of willow. He also 

 affirms the connection between JEcidium leucospermum and Ochrospora 

 Sorbi. 



* Wochenschr. Brauerie. Bd. xxii. No. 9, p. 123. See also Centralbl. Bakt., xv. 

 (1905) p. 61. 



t Oefversigt af Finska Vetensk. Soc. Forkandlingar, xlvi. (1904) No. 2, 23 pp. 

 See also Bot. Centralbl., xcix. (1905) p. 223. 



X Her. Deutsch. Bot. Ges. xxiii. (1H05) pp. 248-50 <\ pi.). 



§ Bull. Soc. Bot. Ital., No. 5 (1905) pp. 158-61. 



|| Ber. Sehw. Bot. Ges., xv. (1905) 13 pp. See also Bot. Centralbl.. xcix. (1905) 

 p. 87. 



