262 THE JOURNAL OF BOTANY 



readers, especially when supplemented by the information that 

 " some botanists mount their plants in albums " (p. 35). 



Apart from the unfortunate " gush " which prevails through- 

 out, the book contains useful suggestions as to collecting and 

 drying plants, " still keeping one principal object in view — to 

 preserve their symmetrical shape." But the suggestions are 

 over-elaborate ; thus a chapter is devoted to "A Nature Note- 

 book," which is "the most important item in the botanical outfit — 

 more important than your herbarium, and, in a sense, even more 

 important than your Flora " (p. 46). How many of our readers, 

 we wonder, keep " a Nature Note-book," and how many of Miss 

 Coley's will attain so comprehensive an ideal as that which she 

 describes ? By the way, if they copy references to flowers into 

 the book, as she suggests, it will be well to assign them correctly. 

 Browning's " dark depth on depth of lustre hid in the harebell " 

 relates to the wild hyacinth, which shares the name with Campa- 

 nula rotundifolia. 



The book includes some useful hints as to popular works 

 which may help the beginner — we regret that the inferior 

 edition of Flowers of the Field (whose author was "Johns," not 

 "John") should be recommended instead of that published by 

 the S.P.C.K. — and an illustrated glossary of botanical terms ; it 

 may thus be regarded as a popular introduction to botanical 

 study, and may prove of service to the beginner. But those who 

 need instruction in collecting will find their wants supplied more 

 efficiently, and more cheaply, in the Instructions for Collectors, 

 No. 10, which may be obtained for 3frf., post free, from the 

 Department of Botany, British Museum (Nat. Hist.). Cromwell 

 Road, S.W. 



BOOK-NOTES, NEWS, dc. 



A comprehensive account of the " Mosaic Disease of the 

 Tomato and related Plants " appears in the June number of the 

 Ohio Naturalist (vol. xiii. pp. 149-173 (1913) ), where Leo E. 

 Melchers has gathered together all the facts relating to this 

 mysterious disease. It was originally described from the leaves of 

 tobacco-plants, but it has also been found on numerous other 

 hosts — petunias, violets, beans, cucumbers, &c. It is, however, 

 more particularly a disease of Solanaceous plants ; it seems to be 

 present throughout the tobacco-growing regions of the world ; it 

 is not uncommon on tomatoes grown under glass, and has also 

 appeared on greenhouse potatoes. The first symptoms of the 

 disease are the mottled, faded spots that cover the leaf, which 

 indicate a serious loss of vitality in the plants attacked. Though 

 many workers have made a study of the disease, the origin of it 

 is not yet definitely ascertained. The most likely theory is that 

 of bacterial action, but bacteria have not yet been conclusively 

 demonstrated. Other causes have been suggested, such as the 

 " Virus " theory or some physiological disturbance. The virus is 

 supposed to be some soluble substance that has a deleterious 



