ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 397 



Cuticles of some Indian Fossil Conifers.* — Ruth Holden gives 

 the following results of her study of several species. A comparative 

 study of living and fossil conifers indicates that epidermal structures 

 are of great value for accurate diagnoses, but of relatively little import- 

 ance for indicating affinities. On account of the character of its cuticle, 

 the so-called Falisst/a iiiiUca of Feistniantel cannot properly be referred 

 to that or any other fossil genus ; and to point out its resemblance to 

 the living Retinospora, ic is suggested that it may be called ReUnosporiUs 

 iiuUca. Echinestrohus expansus closely resembles many living members 

 of the Cupressineaj, both in epidermis and in phyllofcaxy ; accordingly 

 it would seem better to retain the old name of Lindley and Hutton, 

 Thuijitis expansus. Taxitis tenerrimus has a type of cuticle common to 

 many extant conifers, and its affinities cannot l^e decided. The 

 epidermal structure of Fadozamites Janceolatus constitutes another reason 

 for referring that genus to the conifers rather than to the cycads. 



Comparative Anatomy of Box Elder (Negundo).! — As a result 

 of the studies and observations outlined in this paper, A. B. Plowman 

 is of the opinion that the box elder, in its present highly specialized 

 form, is a product of the Glacial Period. The evidence may be stated 

 concisely as follows. Negundo characters were but slightly developed 

 before the Pleistocene or Glacial Period. They have been widespread 

 since that time. Negundo occurs in greatest abundance in regions of 

 the richest glacial drift, especially upon and below the great terminal 

 moraines. Negundo characters were apparently developed rapidly, and 

 partially fixed, through exposure to the inclement conditions along the 

 margins of the great continental ice sheet. It was apparently a primi- 

 tive variant from the ancestral Acer stock, possessing peculiarities 

 especially adapted to glacial- conditions. These features were greatly 

 emphasized by the glacial experience of the species. The impetus 

 gained from glacial influences is not yet lost ; Negundo is highly 

 variable, yet irretrievably separated from the true maples. The nearest 

 points of correspondence are found in Acer penny sylvanica, A. spicatum, 

 and A. pilatinoides. 



Characters of Negundo that would fit it for glacial environment are 

 as follows : {a) leaf morphology and anatomy, indicating maximum 

 utilization of light ,• (Jb) medullary strands in petiole, indicating great 

 capacity for transportation ; (c) extended insertion of leaf-trace into 

 stele ; {d) colour of twigs, indicating energy absorption and protec- 

 tion ; (e) intermediate growth, indicating a maximum growing season ; 

 (/) food storage capacity, indicated by the amyliferous tissue ; {(j) high 

 vitality of lateral buds ; and (/?) vegetative activity of shoots, ensuring 

 quick response to warmth and light ; (/) medullary rays, marginal 

 cells, extension into bark; {j) large and numerous pits in wood 

 elements ; (Jc) bark : thick, tough, elastic, persistent ; (/) unobstructed 

 conduction in roots ; {m) great extent of root system ; (n) large number 

 of seeds ; (o) auemophily ; {p) extreme protection of embryo ; thick, 



* Bot. Gaz., Ix. (1915) pp. 215-27 (1 pL). 

 t Bot. Gaz., Ix. (1915) pp. 169-92 (6 pis.). 



