On the Fertile Shoots of Mesoxylon and an 
Allied Genus. 
BY 
D. H. SCOTT, F.R.S. 
With Plates I-III and three Figures in the Text. 
{* FEB 25 1919 
\ /?/ 
Contents, 
PAGE 
PAGE 
The Fertile Shoots of Mesoxylon 
MULTIRAME . 
Stems of the Mesoxylon Type with 
i a Single Leaf-trace — a New 
Description of the Specimens 
Nature of the ‘ Appendage ’ 
Anatomical Details . 
Discussion .... 
i Genus . 
7 Discussion 
^ Conclusion . 
15 
16 
*7 
*9 
Other Shoots associated with Seeds 
Discussion 
I2 References . 
14 Explanation of the Plates 
20 
The Fertile Shoots of Mesoxylon multirame, 
I N a recent paper on the structure of this species of Mesoxylon (Scott, 
1918, p. 453 ) it was pointed out that the axillary shoots are branch- 
systems of a special kind, entirely different from the relatively main axis 
which bears them. They are characterized by the bilaterally symmetrical 
organization of the shoot, with a much flattened stele, and by the distichous 
branches, which bear reduced leaves or bracts, as well as other appendages 
which may be either prophylls or secondary branchlets. The shoots are 
closely associated with seeds (Mitrospermum compression, A. Arber) and 
may have been the organs which bore them. They are termed ‘ fertile 
shoots as there is little doubt that they were connected with reproduction. 
In the present communication it is proposed to describe these organs fully, 
and to discuss the evidence available as to their function. 
Description of the Specimens . 
In some ways the most important specimen is one shown in immediate 
association with a stem of M. multirame 1 bearing axillary shoots, for here 
we have direct evidence for the fertile shoot belonging to the plant. This 
1 Sections Scott Collection 2564-70. 
[Annals of Botany, Vol. XXXIII. No. CXXIX. January, 1919.] 
B 
