440 SUMMARY OF CURRENT RESEARCHES RELATING TO 



host would not infect the other, and he found also that the perfect fruit 

 form belonged to two different species of Venturia. 



Fungi of the Soil.* — C. J. Koning has published the results of 

 his investigations on humicolous fungi, and on the chemical phenomena 

 that accompany the process of humification. He finds that at each 

 stage of leaf disintegration some special fungus, usually a Hypho- 

 mycete, grows more freely than any other. He notes these fungi, and 

 takes account also of the insects that aid in the distribution and pro- 

 pagation of the different moulds. The leaves that bear the richest 

 crop of fungi are the first to decay ; oak leaves, that provide better 

 nourishment for the fungi, disintegrate more rapidly than those of beech 

 or of pine. The odour of the soil is due to several species of moulds. 

 The author devotes a large part of the work to a discussion of the 

 chemical changes that go on. He states that the process of humification 

 could be explained by the study of chemical phenomena that are pro- 

 duced during the life of the fungus. He gives lists of the fungi found 

 on different trees, and also a list of chemical substances, organic and 

 inorganic, isolated from the soil. 



Disease of Cork Trees.f — F. Bordas has found that the "cork 

 taste " is given to wine by corks that have been cut from a piece of the 

 tree affected with " yellow spot." On examination, the spot was found 

 to be caused by the presence of Aspergillus niger and Pmwillium 

 glaucum. The tree is usually found to be spotted on the side most 

 exposed to rain. Advice is given as the methods to be employed for 

 preventing contamination of the trees. 



Sorica g. n., Parasitic on Ferns.J — K. Giesenhageu describes a 

 curious pyrenomycete from Brazil. It attacks the sori of Polypodium, 

 which become studded with the fructifications of the fungus. There is 

 a black thread-like stalk about 2 mm. in height bearing a perithecium 

 at the apex, which is furnished with a long beak. The spores are 

 globose and brown. The sori of the leaf alone are infected by the 

 fungus : the intervening tissue is free from mycelium. 



Errors in Determination of Fungi due to Misconception of 

 Host-Plants. § — W. Franzschel has inquired into this subject in re- 

 ference to a number of species, and he finds that carelessness in 

 accurately determining the host-plant has led to a considerable duplica- 

 tion of species. Where a parasite has been recorded only once on a 

 somewhat universal host species, the author sees constant reason to> 

 doubt its occurrence at all, and he has several times proved the justness 

 of his surmise. Thus a leaf of Epilobium was confounded with that 

 of a Veronica, leaves of Thalictrum were mistaken for those of one of 

 the Umbelliferoe, and of Plantago lanceolata for those of Scorzonera 

 humilis. 



Fossil Fungi. — Fungi have been recorded by several workers in 

 connection with plants from Palasozoic times, some of them saprophytic^ 



* Arch. Ne'erl. Sci. exact, et Nat., ix. (1904) pp. 34-107. 

 f Comptes Rendus, cxxxviii. (1904) pp. 928-9. 

 I Ber. Ueutsch. Bot. Gesell. xxii. (1904) pp. 191-6 (1 pi.). 

 ' § Ann. Mycol., ii. (1904) pp. 157-61. 



