252 NATURAL SCIENCE. Oct., 



danf(erous and widespread enemy of the cane cultivation of the present 

 day, occurring in greater or less abundance probably everywhere 

 where the plant is grown. Associated with the fungus is a moth- 

 borer caterpillar ; in fact, the insect seems to be the first cause of the 

 disease, as the fungus cannot penetrate the sound plant. The young 

 grubs immediately after hatching upon the leaf-blades make their 

 way down to the protecting leaf-sheath, where they burrow in the 

 soft inner tissues till strong enough to penetrate the cane. The 

 burrows of the moth-borer give entrance to the fungus, and are 

 noticeable as centres of infection. The fungus then rots the cane 

 Various suggestions are made for the destruction of the moth-borer, 

 and the selection of canes capable of resisting the attacks of the fungus. 



Let the humble student of British botany rejoice. A month or two 

 ago we referred to the Brambles as the happy hunting grounds of a 

 little band of clerics. But the Hawkweeds seem even more 

 remunerative, for in the Journal of Botany for August, Mr. F. J. Han- 

 bury, who is tardily and expensively monographing the genus, 

 diagnoses no less than seven new species and two-and-twenty new 

 varieties. As their names indicate, two, Hieracunn surrejaimm and 

 H. cantianuvi, grow close at home, in fact, within fifty miles of London. 

 We do not dread their extermination, in spite of such proximity, 

 except by accident, for like the Brambles and Roses these species are 

 beyond the ken of the ordinary collector, and to quote Mr. Hanbury 

 himself in his mild censure of his Scandinavian colleagues, we " feel 

 it necessary to express a grave doubt as to the practical utility of 

 of such subdivision," and our fear that the study of these genera will 

 be rendered an impossibility, except to the few specialists who may 

 devote their entire lives to their elucidation. 



A NOTE on the germination of seeds in sawdust in the Botanical 

 Gazette for August will be of interest to teachers of Botany. When 

 all goes well there is no better way of getting clean straight roots 

 for class or experimental purposes ; but, unfortunately, the sawdust 

 has frequently a detrimental effect, and roots of plants germinated 

 therein are seen to be in a very unhealthy condition. This, Mr. 

 Stone points out, is due to the presence of tannin, and if only care 

 be taken, to select dust free from this, results will be quite satisfactory. 

 Roots grown in sawdust containing tannin show a reddish colouration, 

 are crooked, and much reduced in size, and this abnormal appearance 

 may be brought about by saturating any sawdust which has been 

 proved suitable for normal growth with a one per cent, solution of 

 tannin. Oak and chestnut dust are, for this reason, to be avoided, 

 while that obtained from Conifers has no prejudicial effect. The 

 writer adds : " We have never experienced difficulty with any 

 sawdust which failed to give the tannin reaction, and during the past 

 year we have used the same sawdust continually without changing." 



