290 Anatomie. 



Davey, A. J., Seedling Anatoray of certain Amentiferae. 

 (Ann. Bot. XXX. p. 575-599. 18 textfigs. 1916.) 



The present paper deals with the seedling anatomy of those 

 forms somewhat loosely classified as the Amentiferaej namely, the 

 earlier cohorts of the Archichlamydeae of Engler, up to and in- 

 cluding the Urticales. The cohorts examined were Verticillatae, 

 Salicales, Myricales, Juglandales, Fagales, Urticales. The species 

 represented cover a wide ränge as regards size of seed and habit 

 of seedling; this point is well illustrated by the author's drawings 

 of a number of the seedlings in question. It is shewn that although, 

 in general, the massive hypogeal seedlings posses the larger number 

 of root poles, there are very stryking instances of the absence of 

 a definite relation between size or habit and the number of root 

 poles present. Thus tetrarchy is equally characteristic of the 

 largest hypogeal seedlings examined (species of Juglans) and of 

 the slender epigeal seedlings of Casuarina (as instanced by Thomas 

 E. N. New Phyt. 1907 p. 85), Myrica, Alnus cordifolia, Carphms^eic. 

 The relatively slender, epigeal seedling of Fagus sylvatica, while 

 resembling in external habit the diarch and tetrarch species of 

 Calycanthus described by Chauveaud and by Thomas, never- 

 theless exhibit diagonal octarchy. (The terms "diagonal" and "cru- 

 ciform" used in this paper are applied in the sense used by Tho- 

 mas, E. N. Seedling Anatomy of Ranales, Rhoeadales, and Rosales. 

 Ann. Bot. XXVIII, 1914 p. 698). 



The author concludes that among the Amentiferae diagonal 

 types of transition are of frequent occurrence, and are correlated 

 with the presence of large numbers of root poles and hypocotyl 

 Strands. Diarchy is characteristic, however, of the Urticales and 

 also of the Piperales described by Hill, Tg. (Ann. Bot. XX. 1906), 

 but is otherwise seldom met with. The form of the vascular Strands 

 in the hypocotyl is remarkably constant, and is that of the triad 

 defined by Dr. E. N. Thomas as the unit of hypocotyl vascular 

 structure. The hypocotyl may contain triad units, in addition to 

 those continuous with the double bundles of the cotyledons, which 

 are related in a similar manner to plumular leaf-traces. Doubleness 

 of plumular leaf-traces occurs very generally. 



Among minor points of interest to which the author draws 

 attention, it may be noted that the seedlings of the Fagales include 

 examples of most of the known types of seedling anatomy together 

 with forms showing transition from one to the other. 



Agnes Arbes (Cambridge.) 



Jeffrey, E. C. and R. D. Cole. Experimental Investigations 

 on the genus Drimys. (Ann. Bot. XXX. p. 359—368. 1 pl. 1916.) 



The authors briefly summarise the work hitherto done on the 

 anatomical results of traumatic Stimulus in the case of the Conifers, 

 which, in their opinion, indicates that ancestral characters reappear 

 as a result of injury. In the present communication they propose 

 to show the value of the study of abnormal material in the case of 

 the non- vascular magnoliaceous genus Drimys. Drimys colorata, D. 

 axillaris, D. Winteri and D. aromatica, as well as Liriodendron, 

 Trochodendron and Tetracentron have been studied. The most im- 

 portant results were obtained in the case of the wounded roots of 

 Drimys colorata which developed peculiar tracheary structures. The 

 structures in question are regarded as the abortive and reversionary 



