1912] Live Oak axd White Oak Seedlings 39 



examined the yoimg roots after a year or two and even reported 

 the results to my dear friend Engelinann, of St. Louis, who 

 had been put on the track by Wm. St. J. Mazyck, who spent a 

 pleasant morning with me at the mill, when 1 was last at 

 Charleston. ..." 



As Mr. Lewis did not publish any late stages of the seedlings, 

 it may be of interest to show the accompanying photograph 

 (Plate II), of three seedlings about fifteen months old taken 

 by me last fall. The plant in the center shows the interesting 

 peculiarity of having a cluster of small tubers Instead of a 

 single large one. 



In one of the above quotations from Dr. Engelmann he asks 

 why the petiole of the cotyledons should be so much longer in the 

 live-oak than in the other oaks. The answer is probably to be 

 found, as suggested in the Proceedings of the Philadelphia 

 Academy, and as expressed by Mr. Lewis, in the "advantages 

 to the plant in establishing itself in the semi-arid situations 

 in which it is often found." In the South-Eastern States at 

 least the live-oak is partial to very sandy soils near the shore, 

 and such soils are necessarily subject to rapid surface desicca- 

 tion. Retention of the food stuff in the cotyledons for a long 

 time would be dangerous, as the cotyledons might be prema- 

 turely dried and killed. 



In regard to the association of fused cotyledons and the 

 tuberous habit, there is a very interesting analogy, that does 

 not seem to have been noticed before, between the live-oak and 

 a number of other dicotyledons. In the development of her 

 theory of the origin of monocotyledons. Miss Ethel Sargant has 

 clearly brought out the existence of a close correlation between 

 the geophilous^ habit and a fusion of the cotyledons. In the Bo- 

 tanical Gazette, for May, 1904, Miss Sargant- has an article on 

 "The Evolution of the Monocotyledons," in which she writes as 

 follows in regard to dicots with fused cotyledons : 



^ The live oak does not, technically, come under Prof. Areschong's definition 

 of a geophilous plant, as it does not periodically lose its above-ground parts ; 

 but it is, nevertheless, a geophilous plant in its youth. 



- See, also. Miss Sarganfs more recent article in Annals of Botany, Vol. 

 XXII, p. 121, 1908, where the literature is given. 



