LINNEAN SOCIETY OF LONDON. 255 



spiralis. — Mr. C. B. Clarke laid on the table dried specimens of 

 the ferns referred to in his paper. — Dr. Marshall Ward read a 

 paper on his ' Researches on the Life History of Heinileia vastatnx,' 

 the fungus of the coffee-leaf disease. The phenomena attendant 

 thereon shows great analogy to those of the Uredine fungi. The 

 spores under favourable conditions, viz., moisture, a due supply 

 of oxygen, and a temperature of 75° F., usually germinate in 

 from twelve to twenty-four hours. Complete infection or esta- 

 blishment of the mycelium in the intercellular passages of the 

 leaf occurs about the third day after the formation of ger- 

 minal tubes. The so-called yellow spot, or ordinary outward 

 visible appearance of the disease, manifests itself about the four- 

 teenth or fifteenth day, but may be delayed, its development and 

 course being dependent on secondary causes, such as atmospheric 

 conditions, monsoons, age of the coffee leaf, &c. By watching the 

 progress of the spots, it has been ascertained that the spores 

 therefrom may be continuously produced for from seven to eleven 

 weeks, or even more. Some 150,000 spores have been estimated 

 as x^resent in one yellow cluster s^Dot, and as 127 disease spots 

 have been counted in one xoair of leaves the quantity of spores 

 thus regularly produced must be enormous. According to amount 

 of diseased spots the sooner the leaf falls, and though young 

 leaves arise the fruit-bearing qualities of the plant necessarily are 

 seriously interfered with. The various sorts of coffee-plant are all 

 hable to infection ; the only possible remedy is the difficult one of 

 destruction of the spores, which are supposed originally to have 

 been introduced from the native jungle and rapidly spread under 

 the favourable conditions of artificial cultivation. 



June 15. — Sir John Lubbock, Bart., F.Pi.S., in the chair. — The 

 following gentlemen were elected Fellows of the Society : — T. D. 

 Gibson-Carmichael, Rev. R. Collie, Chas. A. Ferrier, W. D. Gooch, 

 Sir J. R. Gibson-Maitland, Bart., M. Murphy, Rev. H. A. Soames, 

 H. C. Stephens, H. G. W. Stephens, and James Turner. Mr. Dyer 

 exhibited specimens of Eguisetuiii /jit/antewii from Brazil, which is 

 said to have aerial stems attaining thirty feet. Mr. H. N. Ridley 

 exhibited the monstrosity of Carex ylaiica referred to at page 246. 

 He also exhibited a specimen of Lolium perenne from Hendon, in 

 which the stamens and x)istils were converted mto glumes or glume- 

 like bodies, and in most of the examples terminated by stigmatic 

 hairs, showing the transition from glumes to carpellary leaves. 

 — Mr. G. J. Fookes exhibited and made remarks on malformed 

 specimens of Wallflower and Clematis lanuginosa, var. alba, the Wall- 

 flower resembling in most respects that referred to by the Rev. G. 

 Henslow at a former meeting. — Su- John Kirk exhibited and gave 

 information respecting specimens of the fruits, leaves and rubber 

 of LandolpjJiia Jiorida / obtained from the Island of Pemba, north 

 of Zanzibar ; and also of bells and rubber beaters, made and used by 

 the natives of East Central Africa. — A pa^Der was read by Sir 

 J. D. Hooker, " On Dyeria, a new genus of Apocijnacece from the 

 Malayan Archipelago." Its nearest affinity is no doubt with Al- 

 stonia, from which it differs conspicuously in the sessile stigmas — 



