BOOK-NOTES, NEWS, ETC, 47 



like the rest of the author's work on this group, had two main 

 objects — to contribute to the clear and precise knowledge of the 

 vegetative structure, and to point out, by means of that knowledge 

 the relationship of the Cycads to, and their descent from, fern-like 

 plants. 



At the meeting of the same Society held on Dec. 6th, Dr. 

 Kendle exhibited specimens of Zostera marina from Tibet and of 

 Halophila stipulacea from Tuticorin, and made observations which 

 we hope to publish later. Mr. H. Groves communicated a paper 

 by Mr. G. C. Druce, entitled "A Revision of the British Thrifts" 

 [Statice and Aiiiieria), in which he attempted a rectification of the 

 synonymy, and discussed the value of the pubescence on the ribs of 

 the calyx as a distinguishing character. 



The culture of Citrus trees in Australia is increasing year by 

 year, and the Australian Department of Agriculture has published 

 a little volume by Mr. D. McAlpine — Fungus Diseases of Citrus Trees 

 in Australia — in which is given an exhaustive account of all the 

 fungi that have been recorded on Citrus in the colony. He has 

 found twenty-five species of fungi on the Orange, and thirty- one on 

 the Lemon, besides eighteen common to both ; three species on the 

 Citron, two on the Shaddock, and three which are parasitic on the 

 scale-insects that infest Citrus trees. This formidable list might 

 lead one to infer that these trees were peculiarly liable to attack 

 from fungi; but, fortunately, they are not all parasitic. Many of 

 them, such as PeniciUium glaucum, the familiar blue-mould, Clado- 

 sporiiuii herhanim, and others, make their appearance after decay has 

 set in, and grow on dead Citrus as on any other vegetable matter. 

 The first part of the book, the most important section, deals 

 with the fungi that are directly injurious to the growing plant. 

 The second part is occupied by a description of fungi that are less 

 harmful, or less frequent, grouped as they occur on fruit, leaf, 

 stem, or root. Many of them are confined to Australia alone : 

 as the fruit trees were originally imported from Europe, this seems 

 rather remarkable ; but it is to be remembered that the native 

 Citrus is used as stock in the colonies, and thus native diseases 

 have probably persisted on the grafted plants. The harmful para- 

 sites are all minute species, and occur mostly on the leaves and 

 fruit. One species — Flwma omnivora — attacks the roots, causing 

 root-rot. The book is well illustrated by twelve coloured plates of 

 the diseases most frequently met with, and 186 figures of the fungi 

 causing them ; the numerous new species are fully described, and 

 each is furnished with an " English name," of which " Federation 

 Dothiorella," " Scabbing Ramularia," and '' Corrugating Clado- 

 sporium," may be taken as types. *' Citrus Sphaerella " is not, as 

 might be supposed, a new species of Citrus, but the ''English" 

 equivalent of Sphcerella citricola! Full and careful practical in- 

 structions are given as to the treatment that has been found most 

 efficacious in remedying or checking the pest. 



Just as we go to press, and too late for notice, appears the 

 completion of vol. vii. of the Flora of Tropical Africa, bringing the 



