ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 615 



rust. 5. Influence of cultivation on the intensity of the outbreak. 

 6. Individual or race character of the grain in reference to sensitiveness 

 to attack. Sorauer discusses the questions raised under these headings, 

 and finally sums up that rusts can be overcome only by selecting plants 

 that are immune to attack, and by cultivating such races as are able to 

 withstand the disease. 



Notes on Smut.* — L. Hecke has carried on experiments for four 

 years to test the influence of temperature or of race on the frequency of 

 smut. With regard to summer wheat, the results were so varied that no 

 race influence could be formulated : with winter wheat results were more 

 definite, and pointed to the greater immunity of certain strains. Hecke 

 found that with low temperatures there was more liability to smut. In 

 favourable conditions of warmth, etc., the wheat plant grows quickly, and 

 soon passes the season of greatest susceptibility. 



Notes on Harmful and Interesting Fungi.j — E, Paque records his 

 observations on the gradual destruction of an oak tree by the fungus 

 Fomes igniarius. The stem of the tree was broken at the point of 

 attack, and showed the symptoms of white rot. He describes also the 

 effect of Ar miliar ia msllea on other trees : the rhizomorphic strands 

 take possession of the cambial region, and gradually the tree succumbs. 



A note is added on the culture of Sphserobolus stellatus under a bell- 

 jar, and of its method of ejecting spores. 



Distinctive Characters of the Mycelium of Merulius lacrymans.J 

 J. Beauverie undertook a study of this fungus, the dry-rot of houses, 

 to find if possible some sure method of recognising its presence in 

 wood. He describes the clamp connections of the hyphaj, and the 

 rhizomorphic strands which are peculiar to Merulius but unfortunately 

 not always present. He also studied the nuclei, but they afforded no 

 help in diagnosing the mycelium. 



Dry-rot.§ — Richard Falck has continued his study of the occurrence 

 of dry-rot in wood by examining the types of mycelium belonging to 

 the different fungi that attack timber, and he finds certain characters 

 that might be helpful in determining the fungus. He recommends 

 various methods of destroying the fungus : the true dry-rot of houses 

 can be destroyed by heating the timber to 34° C. 



In another paper || he discusses the same subject. Wood may be 

 attacked in two ways : the mycelium may form a felt on the surface 

 of the wood and gradually penetrate inwards, or the mischief may begin 

 in the interior of the wood and work outwards ; the latter course is fol- 

 lowed by species of Lenzites. Infection takes place always by spores ; 

 they are carried by the wind into cracks of the wood, and, given sufficient 



* Zeitschr. Landw. Versuch. Oesterr., xii. (1909) pp. 49-66. See also Ann. 

 Mycol., vii. (1909) pp. 307-8. 



t Bull. Soc. Roy. Belg., xlv. (1908) pp. 354-7. 



% C.R. Soc. Biol. Paris, lxvi. (1909) pp. 840-2. 



§ Pharm. Zeit., No. 95 (1908) 4 pp. 



|| Jahresber. Ver. Ostdeutsck. Holzhandler Holzind., Berlin, 1908, 18 pp. See 

 also Hedwigia, Beibl., xlviii. (1909) pp. 172-4. 



2 t ° 



