658 Anatomie. — Morphologie etc. 



cies, whether real or only apparent, may be due to one or more 

 of the intervening causes mentioned in paragraph 6. 



4. Species of other North American genera of evergreen Coni- 

 ferae show differences in the width of spring tracheids that may 

 possibly be partly due to differences in afifinity; as species of the 

 same habitat, but belonging to different genera, may differ con- 

 siderably in tracheid width, or, on the other hand, may approxi- 

 mate to agreement. Some of these genera, namely, Torreya, Cha- 

 tnaecyparisj Seqiwia and Jmiiperus, Support the view that the width 

 of the spring tracheid is correlated with available water supplj-; 

 somewhat favoring the view are Cupressits and Picea] indifferent in 

 indication are Abies and Larix. 



5. The theory here propounded derives support from measure 

 ments of the width of the spring vessels of American deciduous 

 species of Querciis. For narrowness and wideness of spring vessels 

 in the main are respectively associated with scantiness and abun- 

 dance of water supply. But in the same kind of habitat the deci- 

 duous black oaks would seem to have narrower spring vessels tban 

 are possessed by the deciduous white oaks. 



6. Though the evidence as a whole strongly favors the theory 

 here propounded, much fuller Information is necessary before a 

 safe conclusion may be drawn. Hence this inquiry and the sug- 

 gestions here given must be regarded as tentative and issued in 

 the hope of stimulating inquiry in regard to factors that may inter- 

 vene, such for instance as the foUowing: climate (including evapo- 

 ration power), exact soil water-content, level of water table, etc., 

 that form the environment of the different species of conifers; also, 

 depth of root, duration of foliage and size of aggregate leaf sur- 

 face, rate of transpiration, width of sap wood, etc., in the different 

 species; also, variations within one and the same species in regard 

 to the features just mentioned, as well as in the width of the spring 

 tracheids, in different habitats. Jongmans. 



Burlin game, L. L., The Morphology of Arancai'ia brasiliensis . 

 II. The ovulate cone and female gametophyte. (The 

 Botan. Gazette. LVII. p. 490—508, with PI. XXV— XXVII, and 2 

 figs. 1914.) 



The ovule possesses a very free nucellus with a glandulär tip, 

 a Single integument adherent to the scale for almost its entire 

 length, a ligule, a large micropyle, and spongy tissue surrounding 

 the gametophyte. 



There is probably a Single functional megaspore, which deve- 

 lops into an embryo sac with about 2000 free nuclei before cell- 

 formation. Cell-formation follows on a peculiar centripetal growth 

 of the cytoplasma and precedes wall-formation, The first walls are 

 formed on the surface of the free cells. Secondary walls are for- 

 med on the spindles of the mitoses occurring in the primary cells 

 of the peripheral regions of the gametophyte. The outer cells are 

 uninucleatc, the inner ones are multinucleate. 



The archegonia have single-tiered necks, usually, consisting 

 of about 12 wedge-shaped cells. The necks are on the surface of 

 the prothallus but are often overgrown. The archegonia maj'^ be 

 Single or occur in complexes and have a singlela3'ered jacket. A 

 ventre canal nucleus may be absent. 



At the end of his papcr the author briefly discusses the re- 



