VOLUME LXI1I 



T H E 



Botanical Gazette 



FEBRUARY 19/7 



A COMPARATIVE STUDY OF WINTER AND SUMMER 



LEAVES OF VARIOUS HERBS 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 224 



J. P. Stober 



Introduction 



The structure of most plants varies with the habitat and even 

 with the varying conditions of the same habitat. This has been 

 emphasized by Grevillius, 1 Chermezon, 2 Cowles, 3 Starr, 4 

 and others. Grevillius made an extensive comparative study of 

 vegetation growing on the island Oland. He compared the plants 

 of a dry, rocky, treeless plain (alvar) with the same species growing 

 ,n favorable regions. The former he calls alvar forms; the latter, 

 normal forms. The alvar forms, in general, were more hairy and 

 had a more highly cutinized and thicker epidermal wall, a more 

 compact palisade parenchyma, and more closely crowded stomata 

 than the normal forms. 



These structural peculiarities due to environmental changes 

 may be observed readily in almost any plastic plant. Oenothera 



1 Grevillius, A. Y., Morphologisch-anatomische Studien iiber die xerophile 

 Phanerogamenvegetation der Insel Oland. Bot. Jahrb. 23:24-108. 1897. 



2 Chermezon, H., Recherches anatomiques sur les plantes littorales. Ann. Sci. 

 Nat. Bot. 12:117-313. 1910. 



J Cowles, H. C, The ecological relation of the vegetation of the sand dunes of 

 Lake Michigan. Bot. Gaz. 27:95-117, 167-202, 281-308, 361-391. 1899. 



4 Starr, Anna M., Comparative anatomy of dune plants. Bot. Gaz. 54: 

 265-305. Ic > 12 - 



So 



