Contributions to the Life-history of Actinostrobus 
pyramidalis, Miq. 
BY 
W. T. SAXTON, M.A., F.L.S. 
Lecturer in Botany at the South African College , Cape Tozvn. 
With Plates XXV-XXVXII and three Figures in the Text. 
HE genus Actinostrobus , Miq., consists of two species of small trees or 
± shrubs confined to Western Australia. Actinostrobus pyramidalis is 
fairly common in the neighbourhood of Perth, but Actinostrobus acuminatus , 
Parlat., is less easily accessible, though locally common on the sand plains 
between the Moore and Murchison Rivers. It has not been possible to 
secure fixed material of the last-named species, but from a study of 
herbarium specimens it is evident that it is very closely related to A. pyra- 
midalis and would be extremely unlikely to show structural differences of 
much importance. 
The present study is a continuation of the series of investigations on 
the structure and development of the Callitrineae, accounts of W iddringtonia 
and Callitris having been already published (19, 20, 21). A very small 
amount of the material for this investigation was collected in January and 
February, 1910 , from a small tree in the temperate house, Kew Gardens, 
and for facilities in connexion with these collections thanks are due to 
Mr. Boodle, Keeper of the Jodrell Laboratory, Kew. 
By far the larger number of collections were, however, made for me, 
and I am glad to take this opportunity of thanking very heartily 
Dr. A. Morrison, late Government Botanist in Western Australia, for the 
great trouble he has taken in securing and fixing material for me in all 
stages of development. He has also placed at my disposal some excellent 
dried specimens of both species of the genus, and has given me interesting 
information in regard to the time of pollination, &c., which has formed the 
basis of the ‘ field notes ’ below. Without his assistance the greater part of 
this study would have been impossible. Thanks are also due to Mr. Stiles, 
who handed over to me some material collected by him at Kew and 
Cambridge Botanic Gardens with a view to working on the genus. This 
material, however, as well as that collected by myself, did not yield anything 
except quite early stages, as, although pollen is plentiful, all female cones on 
the plants growing there become abortive. 
[Annals of Botany, Vol. XXVII. No. CVI. April, 1913.] 
