862 



JOUKNAL OF TilE ROYAL HORTICULTURAL SOCIETY. 



the whole, these park-liko meadows greatly resemble many of the British 

 plant-associations which are intermediate between the deciduous woods 

 and the meadow-associations. The paper is thus extremely interesting 

 to British botanists of the new school. But it is specially remarkable for 

 the manner in which the author has studied the plants of various habitats 

 by physiological experiments &c. The transpiration, amount of starch 

 formed in assimilation, respiration, &c. are recorded in a series of researches 

 which allow of the following conclusions : — Temperature is on an average 

 from 1— higher in open meadows as compared with Ash and Hazel woods. 

 Absolute humidity varies with temperature. Relative humidity differs but 

 little in the various associations. The author does not hold that this is 

 due to the insular climate. The author has repeated Wiesner's observa- 

 tions on the relative light-needs of the various trees (Ash I or Mountain 

 Ash \ to l, Poplar i, Juniper, to fa Hazel T V *° Ai A to ifci 

 Picea exceha .} s to a ' :{ ). J)ying oil' of inner branches begins whilst inner- 

 most leaves are still actively assimilating in cases of Ash, Birch, and 

 Mountain Ash. The Hazel and Oak differ from these. The need for 

 light varies with the nourishment conditions, as is shown by the ortho- 

 tropous shoots of the Hazel. The light available in sunny meadows being 

 taken as 1, that in leafless Ash woods is L to ^, and when the trees are in 

 foliage j 1 ., to in leafless Hazel thickets ^ to and in full foliage from 

 J 7 to fa In Juniper woods the available light is from to in Fir 

 woods fa to fa t and in young Fir woods as little as fa There is a strong 

 assimilation by plants in the spring in leafless woods which becomes 

 almost totally suppressed later on when the foliage is formed. If the 

 maximum starch observed be represented by 5, and 4, 3, 2, 1, represent 

 diminishing amounts of starch observed after the day's work, Dentaria 

 bulbifera gave 5 on June 12 ; on the 25th only 3 (Hazel leaves not fully 

 out), and later only 1 (when the Hazel was in full foliage). Shade-plants 

 assimilate much less than sun-forms of the same species. Starch does 

 not wholly disappear during the short nights of summer in the case of 

 meadow-plants. Respiration is less active in shade-plants than in the 

 same species grown in open meadows. 



Assimilation tissue is far less developed in the leaves of shade-plants 

 as compared with sun-plants of the same species. If, however, the leaves 

 are in sunlight during spring, there is not much difference. Transpira- 

 tion is far less in thickets of Hazel than in sunny open meadows, 

 especially on warm days. Well-developed palisade tissue involves 

 stronger transpiration. Detailed researches are given on all these points. 

 There is a good bibliography, and both the figures of leaf sections and 

 photographs of the associations are excellent. — G. F. S.-E. 



Phyteuma comosum. By B. Othmer (Die Gart. No. 50, p. 596, 



September 10, 1901; with illustration). — One of the prettiest and most 

 interesting of high alpines, not always easily managed under cultivation. 

 The best plants, certain to succeed, are not collected specimens, but seed- 

 lings raised under cultivation. They should be planted in fissures of the 

 rockery exposed to the sun. The flowers are white and violet.— G. B. 



Pigmentation in Fusarium, The Determination of. By E. A. 



Bessey (Flora, xciii. 1 ( J04, pp. 301-334). — The species F. (Neocosmospora) 



