202 SUMMARY OF CURRENT RESEARCHES RELATING TO 



iEcidium found on Ranunculus auricomus. He finds that the alternate 

 form is Uromyces pratensis — the uredo- and teleutospore forms — parasitic 

 on Poa pratensis. 



Feodor Bucholtz * has made a list of the species of Puccinia that 

 have been found in the Baltic provinces of Russia. Such a list, he 

 holds, is most useful in determining the various life-histories. Thus, if 

 one or other form of a heteroecious rust is constantly found in a locality 

 where the alternate host does not grow, the fungus must be able to 

 survive without changing its host. Bucholtz records 102 species, two 

 of which are new. He adds critical notes to many of the species. 



A series of culture experiments have been made by Ed. Fischer f on 

 Uredineae. He found that spores of Pucciniastrum Padi, when sown 

 on the twigs of firs, only produced mycelium in the tissues ; when sown 

 on the flower, tecidia and pycnidia grew in great abundance on the 

 scales of the cones. He has proved also that Puccinia liliacearum 

 grows on Ornithogaium alone, without an alternative host. 



0. Schneider f has continued his work on the Melampsorse of 

 willows. He establishes two new species, Melampsora Ribesii-grandifolicB, 

 the two hosts being Ribes alpinum and Salix grandifolia ; and M. Larici- 

 reticulata, the caoma form of which is found on Larix, the other forms 

 on Salix reticulata and S. hastala, more sparingly on S. herbacea. He 

 notes as a result of his experiments on Melampsora, that many species 

 morphologically similar develop biological differences when there is a 

 wide geographical difference in locality. He contrasts this finding with 

 the specialisation of Puccinia graminis, that has been observed in 

 North America and in Sweden. 



Alfred Hasler % has determined by culture experiment the hosts of 

 six forms of Uredineas, all species of Crepis. He attempted to grow 

 Puccinia Gentaureoz on 18 different species of Centaurea. It developed 

 only on G. valesiaca and G. Gyanus. 



Walther Krieg § records the results of cultures with the aacidiospores 

 collected from species of Ranunculaceae. His results with JEcidium 

 FicaricB were not all absolutely certain, as the host-plants were gathered 

 in the open, and were not free from the suspicion of previous infection. 

 From Ranunculus auricomus he transferred the fungus to Poa pratensis, 

 and obtained a plentiful growth of teleutospores of the type Uromyces 

 Pom. The ^cidiuin on R. platanifolius he found belonged to a type of 

 Uromyces Dactylidis : it grew abundantly on Dactylis glomerata. An 

 iEcidium on Caltha palustris was proved to be an autoecious form, 

 Puccinia Zopfii. 



Ed. Fischer j| writes on the influence of Alpine conditions on the 

 development of Uredineaa. There is a large proportion of reduced 

 forms in Alpine regions. Schneider has pointed out the more rapid 

 development of Alpine species than of those found in the plains. 

 Fischer thinks that this effect is due to climate, and fixed by heredity. 



• Ann. Mycol. iii. (1905) pp. 437-66. 



f Centralbl. Bakt., xv. (1905) pp. 227-32. 



t Torn, cit., pp. 232-4. 



§ Tom. cit., pp. 257-8. \ Tom. cit., pp. 258-9. 



|| Arch. Sci. Phys. Nat., xx. (Geneva, 1905) pp. 572-3. 



