204 



appears to be entitled to the name Sequoia Haydenii (^Hypmini 

 Haydenii Lesq. Ann. Rept. U. S. Geol. and Geog. Surv. Terr. 

 1874: 309. 1876; Sequoia affiiiis Lesq. /. c. 310). 



T. D. A. COCKERELL, 



University of Colorado, 

 Boulder, Colorado. 



REVIEWS 



Two recent Papers by O. F. Cook 



" Origin and Evolution of Angiospcvjus through Aposporyy^ 

 It is suggested in this paper that the phylogeny of the angio- 

 sperms is not to be sought from the bryophytes, up through the 

 cycadofilices, but " more directly in some such primitive condi- 

 tion as the thallose liverworts." The female reproductive appa- 

 ratus of the angiosperms would thus be considered analogous 

 (homologous ?) to the fern prothallia that are borne directly upon 

 the sporophyte without the intervention of spores. 



AntJwccros is named as the most probable hepatic ancestor of 

 the angiosperms, since it is held to be, in point of structure, 

 " farther advanced than the ferns in the direction of the angio- 

 sperms. . . . The independent existence of the vegetative y^////;^- 

 ceros capsule would afford a plant like a seedling angiosperm with 

 its two cotyledons, but bearing spores on the inner surfaces of 

 the cotyledons. No steps are required which have not been 

 closely paralleled in the evolution of one or another of the arche- 

 goniate plants. . . . The part of the angiosperm which, in the 

 present view, might correspond to the prothallus itself, is the 

 nucellus." 



" The fern and the flowering plant are alike in that their 

 ancestors can be traced back to the capsules of simple thallose 

 plants like Anthoceros, but there appears to have been at some 

 very remote point a divergence of procedure, the group which 

 gave rise to the ferns and gymnosperms retaining for a much 

 longer period a functional prothallus which the adoption of 

 apospory enabled the ancestors of the angiosperms to completely 

 eliminate." 



*Cook, O. F. Proc. Wash. Acad. Sci. 9: 159. 1907. 



