598 R. J. HARVEY-GIBSON AND MINNIE BRADLEY ON 



Glavci'iin corniculatum, Bocconia microcatpa, and Eschscholzia califomica. The 

 main stem of Hypecoum grandijlorum is short, and corresponds to the stem bases 

 of types already mentioned. In its upper regions its vascular system consists of 

 from ten to twelve isolated bundles which rapidly increase in number as the base 

 is approached owing to the insertion of leaf-traces. Lateral fusion then takes place, 

 and finally the vascular system forms a complete ring broken only at intervals by 

 the entry of leaf-traces. The xylern vessels are abundant, and the stem contrasts 

 in this respect with the preceding types. The anatomy of the stem base in Dicentra 

 formosa closely resembles that of Hypecoum, as does also that of Romneya trichocalyx. 

 In the genus Corydalis the features are in all respects similar, save for certain un- 

 important variations in the degree of sclerosis of the cortical and medullary cells 

 and in the amount of secondary wood formed and the extent of its lignification. 



The course taken by the vascular strands in Papaver Rhceas has been already 

 described, but a few notes may be added as to conditions obtaining in this respect in 

 other species of Papaver and in other genera of Papaveracese. So far as the course 

 of the bundles in species of Papaver is concerned, it may be said at once that it 

 differs in no essential from that found in P. Rhceas. In Meconopsis cambrica the 

 capsule contains four placental plates with four placental vascular strands, while the 

 peduncle contains a ring of several isolated bundles which exhibit frequent fusions 

 and splittings. In Argemone mexicana there are also four placental bundles, 

 horseshoe-shaped in section. Each opens out and fuses laterally with its neighbours 

 so as to form a ring of vascular tissue prior to the entry of the stamen traces. 

 Small leaves are attached close to the top of the peduncle, and their method of entry 

 is shown in fig. 31, a, b, c. 



In Chelidonium majus the flowers are arranged in corymbs, though some authors 

 regard the inflorescence as a true umbel. The vascular tissue, however, shows that 

 the main axis gives off a series of bundles to small bracts each with a flower-stalk in 

 its axil, the whole arranged in a close spiral. The ovary consists of two carpels, and 

 the strands from each of these, together with those from other floral parts, form in 

 the pedicel a circle of four large and three or four smaller bundles which follow 

 independent courses until the base of the pedicel is reached, where they fuse to form 

 a vascular ring. The bract trace consists of a single bundle, and the vascular system 

 of the pedicel at the point of attachment to the main axis splits, one-half being 

 thrown to either side of the bract trace, all three cords entering by a gap formed in 

 the vascular system of the chief axis. The bract traces tend to become multi- 

 fascicular in the lower regions. 



The course of the bundles in Glaucium corniculatum does not differ in any 



essential respect from that described in Papaver Rhoeas, while that seen in 



m Bocconia microcarpa closely resembles the arrangement in Chelidonium majus. In 



Eschscholzia califomica the five vascular cords from the carpels fuse into a ring at 



the base of the ovary, to which are attached the cords from the stamens and petals. 



