Biologie. — Cytologie u. Befruchtung. 131 



Schildert das Aussehen, die Lebens- und Grössenverhält- 

 nisse der in den Gärten auf den Faer-Oeern angepflanzten 

 Bäumen. Die ungünstigen klimatischen Verhältnisse, Stürme, 

 kühle, nebelige Sommer, sehr unruhiges und oft recht kaltes 

 Winterwetter, bieten dem Baumwuchs erhebliche Schwierig- 

 keiten, die bis jetzt angepflanzten Bäume sind gewöhnlich 

 nur klein, und die über die Krone hinausragenden Jahrestriebe 

 sterben gewöhnlich im Winter ab. Trotzdem empfiehlt Verf. 

 erneuerte Versuche mit rationell ausgesuchten Baumsorten auf 

 fachgemäss behandeltem und gepflegtem Boden. Porsild. 



Weiss, F. E., Observations on the pollination of the 

 pr im rose. (The New Phytologist. Vol. II. 1903. Nos. 4 

 und 5. p. 99—105.) 



Large quantities of primroses, growing in a sheltered 

 Position near Church Strelton in Shropshire, were observed 

 this Easter and the following insect-visitors noted: 17 Bombyliiis 

 major, 3 Bombiis terrestrls, 7 Anthophora furcata , 1 Apis 

 mellifica. The first of these is undoubtedly an active agent in 

 the pollination of the primrose and seemed at this time of the 

 year to confine is attention to the primrose; this latter also 

 seems to be the case with Anthophora. Andrena Gwytiana, 

 which greedily gathers the pollen of the primrose, can be an 

 active agent only in the pollination of the long-styled flowers. 

 The author points out that unfavourable weather is prejudicial 

 to the cross pollination in many piaces owing to the absence 

 of insects and thus explains Darwin's and BurkilTs obser- 

 vations. In many of the primroses examined Thrips was 

 present and in these cases self-pollination is probably the rule. 

 The changes in the position of the flower of both the primrose 

 and the cowslip are also regarded as to some extent an adap- 

 tation for self-pollination, which is of value to a plant flowering 

 at a time of the year when insects are scarce. f. E. Fritsch. 



Blackman, V. H., On a new method for facilitating the 

 staining of microscopically small objects. (The 

 New Phytologist. Vol. II. 1903. Nos. 4 and 5. p. 105— 107.) 



The material is very gradually brought up to some Clearing 

 fluid (a mixture of equal parts of xylol and cedar-wood oil being 

 perhaps the best) and drops of the latter, containing the objects 

 are then placed upon a slide, prepared with egg-albumen. 

 After evaporation of the fixing fluid, absolute alcohol is allowed 

 to flow slowly over the slide, the former being thus removed 

 and the objects retained in position by the coagulated albumen. 

 The slide is then treated as in the case of microtome series. 



F. E. Fritsch. 



9* 



