118 THE JOURNAL OF BOTANY 



also very leathery fronds, this argument per contra failed. One of 

 the specimens of A. marinum exhibited with Scolopendroid sori in 

 quantity, found in France, might also, he considered, possibly be a 

 natural hybrid with S. vnh/nre, especially as its fronds and some 

 pinnae were peculiarly forked, dilated, and irregularly abnormal ; 

 while it is well imown that the two species are often closely asso- 

 ciated in their habitats, so that their spores might easily mix. 



At the meeting on Feb. 7th, the President, Prof. S. H. Vines, while 

 demonstrating the property possessed by certain vegetable liquids, 

 such as coco-nut milk, and the juice of the pineapple and the potato, 

 to cause the oxidation of guaiacum tincture in the presence of hy- 

 drogen peroxide, a blue colour being produced, drew attention to the 

 recent researches of Kaciborski on the subject. Kaciborski has made 

 the interesting discovery that certain tissues of the plant-body, more 

 particularly the sieve-tubes and the laticiferous tissue, contain some 

 substance, to which he gives the name leptomin, which likewise causes 

 guaiacum to turn blue in the presence of hydrogen peroxide, and has 

 gone on to infer that this leptomin may be regarded as discharging in 

 the plant a function analogous to that of hasmoglobin in the animal 

 body. It was urged, against this assumption, that, although both 

 leptomin and haemoglobin give the guaiacum reaction, yet this fact 

 does not prove that leptomin can combine with oxygen, and can act 

 as an oxygen-carrier in the organism, in the manner which is so 

 characteristic of haemoglobin ; and that therefore the suggested 

 analogy between the two substances is at least premature. 



Mr. Carruthers, as consulting botanist of the Royal Agricultural 

 Society of England, has recently reported on a fungoid disease of 

 the leaves and fruit of cherry-trees. This report has been issued as 

 a leaflet by the Society. The fully-developed fungus, Gnomonia 

 erythrostoma, belongs to the group of Pijrenomycetes. It makes 

 its appearance in spring on the young green leaves, causing yellow 

 spots, which gradually increase in size. On these spots small peri- 

 thecia are formed, containing long curved stylospores, which further 

 spread the disease. The cherries are attacked at the same time as 

 the leaves, and rendered unfit for market. The diseased leaves die 

 early, and remain attached to the branches during the ensuing 

 winter. Towards early summer the perfected form of the fungus, 

 a round black perithecium that tapers up into a beak, is developed 

 on the dead leaves, and produces the ascospores which reinfect the 

 young leaves. The early death of the leaves and the consequent 

 want of nourishment causes the branchlets to become dwarfed, the 

 internodes between the leaf-bases being scarcely developed. Mr. 

 Carruthers has followed Prof. Franke, of Berlin, who has carefully 

 studied the fungus, in his diagnosis of the disease and in the remedy 

 recommended. The dead leaves should be plucked and burned 

 before the new foliage has begun to grow, and thus the source of 

 infection would be removed. This would doubtless be a troublesome 

 and expensive procedure, but it commends itself by its thoroughness 

 and simplicity. It is in the orchards of Kent that the disease has 

 appeared during the last few years, and it has already spread widely. 



