168 Algae. — Fungi, Myxomyceten , Pathologie. 



Distribution, General features, The Bulbus, Mode of growth of 

 tubercles, The pro-embryo, Transitions from rhizoid to pro-embrj^o , 

 Pro-embryo arising from the oospore, Abnormal plants. The sum- 

 mary of her results is as follows: Under cultivation in jars in which 

 there was no special provision for aeration but in which the water 

 was from time to time changed, L. alopecuroides has flourished 

 vegetatively for several j^ears, showing its characteristic growth and 

 producing an abundant supply of both antheridia and oogonia. 



Apparently a very small number of spores are capable of ger- 

 mination, producing a pro-embryo of characteristic growth. 



The pro-embryos produced from the oospores resemble those 

 produced from the Underground nodes of the plant. 



In many cases the pro-embryo differs from that of other Chara- 

 ceae by the interposition of an extra oblique node, from which 

 rhizoids are produced. 



In the case of the pro-embryos produced from the rhizoid-node's 

 bearing tubercles, about 30 per cent showed this interposed node. 



For the most part reproduction takes place by means of pro- 

 embryos, which are formed on the rhizoid-nodes and make use ot 

 the starch stored up in the tubercles. Brauch pro-embyros are rare. 



Sometimes pro-embryos arise from rhizoid-nodes bearing no 

 tubercles, or from the rhizoid-node of another pro-embryo. 



The tubercles either originate directly as such, or are formed 

 by the transformation of rhizoids. 



The terminal rhizoid of a tubercle may again become transfor- 

 med into a tubercle containing starch, thus forming a series of two 

 or more tubercles. 



The pro-embryos arise at the basal side of the tubercle. 



Generally several pro-embryos arise from a node bearing tubercles. 



The nuclei of the tubercles are fragmented, as in the case of 

 the internodal cells. E. S. Gepp. 



Philip, R. H., Notes on Diatoms in 1906. (Transactions of the 

 Hüll scientific and Field Naturalist' Club for 1906. Vol. III, part. 4. 

 Hüll. p. 291—292. 1907.) 



The author gives a list of the most interesting species of Diatoms 

 which were collected in Yorkshire during 1906. In all, 18 species 

 and a variety are mentioned and 7 of them are figured. Strangely 

 enough, Coscinodiscus vadiatus, a marine species, was found well 

 above high water mark in a stream which falls into Little Thorn- 

 wick Bay. E. S. Gepp. 



Aderhold, R. und W. Ruhland, Der Bakterienbrand der 

 Kirschbäume. (Arb. d. Kais. Biol. Anst. f. Land- u. Forstw. V. 

 6. m. 1 Taf. und 12 Textfig. 1907.) 



Vorliegende Krankheit wurde zum ersten Male im Frühjahr 

 1905 in Baumschulen und jüngeren Pflanzungen entdeckt, verschont 

 jedoch auch ältere Bäume nicht ganz. Die Krankheit tret sehr ver- 

 derblich auf; in einigen Fällen gingen 50— 60*^/o der Bäumchen 

 daran zugrunde. 



An den kranken Bäumen zeigten sich grosse, tote Rindenstellen, 

 meist etwas eingesunken und von Ueberwallungsrändern umgeben. 

 Die Bäume hatten im Frühjahr nicht ausgetrieben oder sterben 

 während des ersten Triebes ab. Häufiger noch welkten die Kronen 



