NOTES ON EECENT RESEARCH. 



89a 



ing amounts of calcium and magnesium salts on the growth of plants, 

 and to study the ameliorating effects of lime salts in overcoming the 

 poisonous results of an excess of magnesia. 



The results show that the best proportion of soluble lime to soluble- 

 magnesia for the germination and growth of plants is about 7 to 4 actual 

 weight, or 5 to 4 molecular weight. 



Sulphate and nitrate of lime were more efficacious in overcoming the 

 noxious effects of magnesia than the less soluble salts of lime. 



When the lime in a soil is about equal to or less than the magnesia, 

 present, finely powdered sulphate of lime should be applied whenever 

 crude Stassfurt salts, such as kainit and carnal! it, are used as manures. 



/. P. 



The Pear-tree and Mistletoe. 



Mistletoe, On the Existence of a Substance in the Berries,. 

 Seeds, and Embryo of. Poisonous to the Pear. By Emile 

 Laurent (Comjj. Bend. December 2, 1901). — The germination of Mistle- 

 toe seeds on the branches of certain varieties of Pear — ' Williams, 

 ' Josephine de Malines,' &c. — is followed by the death of these branches 

 during the summer. 



The branches of Spartium junceum and Ficiis elastica are also killed 

 by the germinating seeds of Mistletoe. 



In the case of the Pear, the bark is killed and contracted to a distance- 

 of some inches from the point of inoculation. The vessels are also 

 clogged with a gummy substance, which checks the flow of the sap ; 

 consequently the leaves fade and die, followed by the death of the entire 

 branch. In such cases the young Mistletoe never enters the tissues of 

 the Pear, but also perishes. Such varieties of Pear are immune against 

 the attacks of the Mistletoe. 



The toxine or poisonous substance is most abundant in the embrvo of 

 the Mistletoe seed, and becomes diffused into the pulp of the berry during 

 germination. — G. M. 



Anatomy of Sphagnum. 



Mosses, Researches on the Anatomy and Biolog-y of. By 



W. Lorch (Flora, vol. Ixxxix. 1901, pp. 434-454; 32 cuts). — Contains an 

 account of the formation of the perforations in the walls of the large 

 cells of Sphagnum, which give it its peculiar spongy character. — M. H. 



Nature of Ozonium. 

 Ozonium auricomum. By Charles B. Plowright, M.D. {Trans. 

 Brit. Myc. Soc. 1900-1901). — Producing evidence that the common 

 golden-yellow fibrous substance called Ozonium, which has been a puzzle 

 for so many years, and supposed to be the mycelium of some Poh^^ore, 

 is in reality the mycelial condition of Coprinus domesticus, a black-spored 

 deliquescent Agaric, which is not uncommon in this country. In this 

 instance the Ozonium was developed in an earthen vase in which a pot 

 of Aspidistra was growing, and, passing through the mould to the light, 

 produced there the stems and pilei of the Coprinus. Another instance 

 is given in which a decayed stick was found with a Coprinus on its upper 

 side and a mass of Ozonium on the lower. — M. C. C. 



