422 Lang . — Studies in the Development and 
In these studies the attempt will be made to examine and 
compare the development and mature structure of the 
sporangia of those Cycads that have not been fully investi- 
gated, so far as material can be obtained. The difficulty of 
obtaining suitable material for developmental work is very 
great in plants of this group ; but the magnificent collection 
of Cycads in cultivation at the Royal Gardens, Kew, which 
in many cases bear cones freely, affords a peculiarly favourable 
opportunity for gradually accumulating material of the various 
stages. This investigation was commenced at the suggestion 
of Dr. D. H. Scott in the Jodrell Laboratory at Kew, upon 
material already collected by him : and this material was 
supplemented with further stages as opportunity offered. 
In connexion with the collecting of material, I wish to 
acknowledge my indebtedness to the authorities of the Royal 
Gardens, who, whenever possible, readily gave me permission 
to preserve the cones which were produced on the different 
species. The removal of young cones without inflicting 
injury on the plants is an operation that requires great care, 
and in this and other ways Mr. Watson kindly assisted me. 
The work was commenced under the guidance of Dr. Scott 
in the Jodrell Laboratory, and has been continued at Glasgow 
University. To Dr. Scott and Dr. Bower I wish to express 
my thanks for numerous suggestions and other valuable 
assistance in the course of the investigation. 
Two courses are open in recording the results obtained. 
The observations made on the considerable amount of material 
of a number of genera might be collected together, and sup- 
plemented when the stages which were wanting could be 
obtained ; or the publication of the results on each genus 
might be deferred until a fairly complete account of the 
development of its sporangia was possible. The latter course 
has many advantages, and will be followed. 
The present paper deals with the development and structure 
of the microsporangia of Stangeria paradoxa , Th. Moore. 
Since it has not been possible to obtain the earliest stages 
of the development of the ovule, the full account of its de- 
