546 Fungi, Myxomyceten , Pathologie. 



physiological species of the mildews, pointing out that the results 

 so far obtained indicate that these various physiological species of 

 'aildews have definitely limited powers of infection. He then presents 

 the results of a number of infection experiments with the mildew 

 on cucurbits made in order to determine whether specialization 

 has also occurred in this mildew. He identifies the cucurbit mildew 

 as Erysiphe cichoraceanirn DC. He inoculated the spores of this 

 mildew on to various cucurbits, using twenty-three varieties be- 

 longing to five different species representing the genera Cucurbita^ 

 Cucumis and Lagenaria. Each of these types was readily infected 

 when inoculated with the conidia taken from any other. There was 

 no difference in the infecting power of the mildew on the different 

 species and genera, the fungus readily passing from plant of one 

 genus to plants of either of the others. The author points out that 

 this result is in striking contrast with those previously obtained with 

 the mildews on other host plants; in other words, that there is no 

 evidence of any specialization in the mildew of this family. He com- 

 pares the results of his experiments on cucurbits with Salmon's 

 experiments on grasses where the latter found four or five physiolo- 

 gical species. Reed suggests that it is possible that the condition 

 found in the mildew of the Brome grasses is the more primitive 

 one and that the mildew of the cucurbits represents a further step 

 where a particular parasite has become adapted to live on a much 

 wider ränge of hosts. A bibliography of thirty-nine titles is appended. 



Von Schrenk. 



Roques, E, G., Les Champignons parasites des plantes des 

 Pyrenees. (Bull. Soc. bot. France, 22 mars 1907, t. LIV,p. 141 — 146.) 



Dans cette note de parasitologie alpine, l'auteur Signale au jardin 

 alpin du Pic du Midi: Fusicladiuni Aronici Sacc. sur Aronicum 

 scorpioides DC, Synchytriuni aureunt Sehr, sur trois hOtes nouveaux: 

 Hutchinsia alpina, Galium caespitosum, Oxytropis pyrenaica , Pyveno- 

 phora chrysospora (Niessl.) Sacc, forma glacialis. Le Synchytriwn 

 aureunt est egalement Signale au Canigou sur Phyteu)na spicatum , 

 matrix nova. Signalee par Karsten au Spitzberg et ä Beeren 

 Eiland, la forme glacialis du Pyrenophora chrysospora parait repre- 

 senter dans les Pyrenees un des vestiges de la flore mycologique 

 des temps pleistocenes, ce Champignon ayant emigre des regions 

 polaires ä l'epoque glaciaire. P. Vuillemin. 



Trotter, A., Cynips Fortii n. sp., descrizione ed istologia di 

 una nuova galla d'Asia Minore. (Marcellia, VI (1907), p. 12—23, 

 avec 5 figures intercalees dans le texte.j 



Sur un echantillon de Quercus lusitanica recolte en 1900 en 

 Asie Mineure, l'auteur a reconnu des galles qui remplacent les 

 fruits dont elles ne sont qu'une profonde modification. Ces galles sont 

 produites par une nouvelle espece de Cynips, le C Fortii Trotter n. sp. 



Apres avoir decrit l'insecte et la galle, M. Trotter fait ressortir 

 que parmi les galles, celle-ci se rapproche surtout de celle produite 

 par le Cynips Theophrastea Trotter. II decrit soigneusement la struc- 

 ture histologique des differentes regions de la galle en montrant que 

 son developpement doit commencer peu avant la differenciation des 

 organes, ou que l'oeuf doit etre depose dans un endroit d'oü il puisse 

 reagir sur les tissus primordiaux de la cupule et du gland: en effet, 

 dans le voisinage des galles completement developpees toute trace 



