XV] GYMNOSPERMS 139 



E, female flower of S. alba in longitudinal section; .F, female flower of S. 

 pentandra; G, of S. tetrasperma; H, of Populus tremula in section. J, seed 

 of Populus; K, of Salix in longitudinal section. L, floral diagram of male 

 flower of S. Caprea; If, of S. triandra; N, of S. pentandra; 0, of Populus 

 tremula. P, diagram oFfemale flower of S. Caprea ; Q, of S. alba; R, of 

 Populus. S, diagram of hermaphrodite flower of S. Caprea. In all cases 

 n indicates stigma; d the disc or glands (E and P). 



often larger, differently shaped, and even more delicate 

 in texture and colour than the carpellary scales above. 



In all the foregoing cases we see that the extreme 

 simplicity of the flower is expressed in three peculiarities. 



In the first place, the very simple nature of the floral 

 organs : there is no definite perianth, and each flower 

 consists of either a few or many stamens, or of one or 

 more ovules, with or without carpellary scales. 



Secondly, the carpellary or staminal scales are mere 

 scales, and not differentiated far from the structure of 

 other scales or scale-like leaves on the plant. 



In a third peculiarity we have something totally 

 different from the normal state of affairs in a typical 

 flower viz. the ovules are not covered in a closed 

 ovary : the carpellary scale, when it exists, does not fold 

 over the ovule or ovules, and thus the latter are naked, 

 or exposed, a feature of fundamental importance, and 

 which Robert Brown, in 1827, emphasized by calling 

 these plants Gymnosperms, or naked-seeded plants with 

 open carpels. 



But even in flowers of the higher series of seed-plants, 

 called Angiosperms because their ovules are always en- 

 closed in a box-like covering formed of closed carpels 

 the ovary or pistil we find very simple flowers among 

 the lower members of the group. 



Among the simplest are the flowers of the Willows 

 and Poplars. 



If we dissect off carefully one of the scales of a female 



