24 



PRINCIPLES OF PLANT-TERATOLOGY. 



as to the nature of the double scale in Abietinese, 

 Cupressinese, Gryptomeria, Taxodium, and Glyptostrobus, 

 yet argues that in Agathis, Araucaria, Cunninghamia, 

 Sciadopitys, Sequoia, and Athrotaxis we have to do with 

 a simple, not a compound structure. This view of his 

 is based on the following facts : that the scale shows 

 no obvious signs of its compound nature ; and that in 

 Sequoia sempervirens, which bears no close relationship 

 to Taxodium, he observed androgynous cones in which 

 some of the scales bore pollen-sacs on the lower and 

 ovules on the upper surface, while other scales, similar 

 in all respects to the ordinary pollen-sac-bearing scales, 

 bore ovules on their upper surface, this fact proving 

 that there is but a single scale present. But the 

 probabilities are that in an abnormal cone of this sort 

 in which the nutritive conditions were very much dis- 

 turbed, the true male scales might very easily come to 

 bear ovules ; for we know many cases of ovuliferous 

 stamens. Again, Velenovsky does not take into con- 

 sideration the fact that Engelmann, in America, found 

 a proliferated cone of Sequoia, which clearly exhibited 

 the compound nature of the scale. And it is probable 

 that Sequoia, is sufficiently nearly allied to Taxodium 

 to warrant the position that the structure of the 

 ovuliferous scale in each must be identical. In Taxo- 

 dium, Gryptomeria, and Glyptostrobus, A. Braun found 

 an axillary bud replacing the scale. 



Velenovsky is most likely misled by the extreme 

 intimacy of the union of the two scales to which the 

 apparent simplicity of the double scale is doubtless 

 due. Again, the anatomical structure of the scale of, 

 e. g. Araucaria, with its upper series of inversely- 

 orientated vascular strands, is so similar to that of the 

 Abietinean scale as to suggest that the two are 

 similarly constructed. 



Although the other views as to the nature of the 

 ovuliferous scale have not all to do with abnormal 

 axillary branching, they may be introduced while this 

 subject is being dealt with. 



