ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 519 



apetalous flowers, but to the way in which the bee enters the flower. 

 In absence of the petals the insect enters the flower in such a way that 

 it does not carry pollen to the stigmas. The difference in seed product 

 is therefore due to the difference in the efficiency of cross- (in the 

 petalous) and self-pollination (in the apetalous flowers). The author 

 found that the fewer seeds produced in the flowers from which the 

 petals had been removed, had the same germinating power as the seeds 

 of normal flowers. 



Determination of Dominance in the Colour Characters of Hy- 

 brids.* — Correns points out that in determining the dominance, absolute 

 and relative, of colour characters of hybrids the psychological characters 

 have been neglected. According to the well-known law of Fechner, 

 apparent intensity of colour to the eye varies only as the logarithm of 

 the actual intensity (concentration) of colour. It is clear that this 

 would lead to serious error when comparing the relative effect of parents 

 in relation to the colour of a hybrid. In order to reduce such an error 

 as much as possible Correns used various thicknesses of coloured solu- 

 tion with which the colours of the parents and hybrid were compared, 

 so as to obtain a numerical expression of the depth of tint. By this 

 method the question of colour dominance was accurately investigated 

 in Argemone mexicana x A. ochroleuca, in Mirabilis Jalapa x M. Jala/pa 

 var. aurea, and in Melandrium album x M. rubrum. 



Aristolochiacese.f — L. Montemartini alludes to the different views 

 held by several botanists as to the systematic position of the Aristolo- 

 chiacere ; and in order to furnish future students of the group with 

 materials for determining its position with greater certainty he puts on 

 record his researches into the anatomical structure of Aristolochia and 

 Asarum europium. His observations of the vegetative organs confirm 

 those of Solereder and of Schellenberg. The reproductive organs he 

 describes in greater detail. 



t>' 



German Flora.! — The report of the Commission embodying new 

 observations and records for the Flora of Germany, 1899-1901, occupies 

 a recent number of the Berichte of the German Botanical Society. Th. 

 Schute and Iv. W. von Dalla Torre are responsible for the portion 

 dealing with seed-plants. The bibliography includes 630 papers arranged 

 alphabetically under the name of the author, and there is also a list of 

 new local records arranged systematically under the plant-name. 



Flora of Chinai — C. H. Wright contributes an elaboration of the 

 orders Haernodoracese, Iridese, Amaryllideae, Dioscoreacea?, and Liliaceas, 

 to Messrs. Forbes and Hemsley's enumeration of Chinese plants. 



Plants of Lord Howe Island. || — J. H. Maiden supplies notes on 

 a few plants from this island, including a new species of Cryptocarya. 



* Ber. Deutsch. Bot. Ges., xxi. (1903) pp. 133-47. 



+ Atti d. Istit. Bot. Univ. Pavia, vii. (1902) pp. 229-50 (12 pis.). 



t Ber. Deutsch. Bot. Ges., xx. Generalvers.-heft, il. (1903) pp. 103-72. 



§ Journ. Linn, l-'oc. xxxvi. (1903) pp. 73-136. 



j| Proc. Linn. Soc. New South Wales, xxvii. (1902) pp. 347-51 (1 pi.). 



