CONIPERALBS 



75 



ment of bundles in the arc showing that the axillary structure 

 is a leaf and not a branch; and that the reversed orientation 

 shows that the leaf belongs upon the suppressed branch opposite 

 the bract. This is not Robert Brown's view of an axillary car- 

 pel, but rather Alexander Braun's view that the ovuliferous 

 scale is the leaf of an axillary branch. 



In 1871 Von Mohl ^* further strengthened Braun's position 

 by the publication of his studies of the peculiar " double leaf " 

 of Sciadopitys. He showed that this leaf represents the first 

 two leaves of an axillary shoot, which stand transversely, and 

 which become coalescent by their posterior (toward the axis) 

 edges, the vascular bundles thus showing reversed orientation. 

 As this normal behavior of the leaves of Sciadopitys exactly 

 parallels what was claimed by Braun for the ovuliferous scale, 

 the results of Von Mohl are almost in the nature of a demon- 

 stration. 



In 1872 Strasburger ^'^ announced his adherence to the view 

 that the ovuliferous scale is a flattened axis, at the same time 

 combating the idea of gymnospermy. While later ^* his views 



ABC 



Fio. 60.— Microsporangia from the strotili shown in Fig. 59: A, normal sporophyll, 

 side view ; S, slightly modified sporophyll from summit of a bisporangiate stro- 

 bilus ; and D, side and front views of sporophylls from summit of a bisporangiate 

 strobilus ; E and F, side and front views of sporophylls from the base of a bispor- 

 angiate strobilus. 



in reference to gymnospermy became modified, he held to the 

 axial nature of the scale. 



In 1876 Stenzel ^° described striking abnormalities in Picea 

 excelsa. In one cone leafy axes occurred in the axils of the 

 bracts, the first two leaves resembling ovuliferous scales more 

 than ordinary foliage leaves in texture. In other cones the 

 abnormalities recorded by Dickson ^ were observed. In still 



