484 SUMMARY OF OUKRENT RESEARCHES RELATING TO 



Pollen of Gymnosperms.*— In contintiation of his previous ob- 

 servations on tins subject,! Dr. L. Juranyi now states that the male 

 prothallium of Ephedra altissima is formed in precisely the same way 

 as in Cycadea), not from the small cells of the pollen -grain which arc 

 first separated, but by successive divisions of the larger cell. 



Ant-harbouring Organs of Plants.t— Dr. O. Beccari describes those 

 plants, natives of Malacca and Tapua, which possess " extra-floral 

 nectaries," or receptacles for honey outside the flowers which attract 

 the visits of ants and other insects. He believes that the production 

 of the galleries and other striicturcs in which this secretion takes 

 place, e. g. in Murmecodia, is an acquired hereditary character, re- 

 sulting in the first place from the irritation caused by the punctures 

 of the tissues by the insect. 



Malformations caused by Insects.§— Dr. F. Krasan describes the 

 injuries caused to the oak by the laying of the eggs of Orchcstes 

 Quercus ; their growth is arrested, they curl and roll back, and become 

 thicker and more rigid than the ordinary leaves, giving a very peculiar 

 appearance to the tree. In Jime these arc followed by a second 

 growth of leaves, of very large size, and scarcely resembling the 

 ordinary ones ; and later by a third growth of normal leaves. To 

 these phenomena Krasan gives the names megalophyllosis and pachy- 

 phyllosis. These distortions may even become hereditary, and cause 

 the appearance of apparently new species ; as in the case of Quercus 

 hrachyj^hylla Kotschy, probably derived from Q. puhesccns. Similar 

 malformations occur in several species of Abies and in Thymus 

 serinjllum. 



Bower and Vines's Practical Botany. II — We have here the long 

 needed desideratum of a practical guide for students in laboratory 

 work. After five introductory chapters, viz. (1) Making Preparations ; 

 (2) Micro-chemical Eeagents ; (3) General Structure of the Cell ; 

 (4) Micro-chemistry of the Cell ; (5) Micro-physics of the Cell, the 

 authors describe the various points of structure which the student 

 has to look for in the different parts of flowering plants, Dicotyledons, 

 Monocotyledons, and Gymnosperms, succeeded by the following types 

 of Vascular Cryptogams: — Selaginella, Lycopodium, Aspidium, and 

 Eqidsetum. The present part is intended to be followed by another 

 comprising the remaining types of the vegetable kingdom. The work 

 is the result of long experience in the practical teaching of botany 

 with the aid of the Microscope ; the descriptions are given through- 

 out in clear and terse language, and the work is indispensable to the 

 teacher and of very great value to the learner. 



* Magy. Tud. Akad. Ertesito, 1884 (3 pis.). See Bot. Centralbl., xxi. (1885) 

 p. 76. 



t See this Journal, iii. (1883) p. 84. 



i Beccari, O., ' Maleaia,' vol. ii. 4to, Genova, 1884, 36 pp. 



§ Engler's Jahrb., v. (1884) p. 351. See Naturforschcr, xvii. (1884) p. 340, 



II Bower, F. O., and Vines, S. H., 'A Course of Practical Instruction in 

 Botany.' With a Preface by W. T. Thiselton Dyer. Part I.—' PhanerogamiB— 

 Pteridopbyta.' 8vo, London, 1885. 



