MB. G. BEKTHAM ON EUPHORBIACE^. 203 



(Hippomanese). In aid of this explanation various published 

 diagrams may be referred to, especially the plan given by Baillon, 

 1 Histoire des Plantes,' v. 105, f. 145, noting, however, that it is 

 purely diagrammatic, not the plan of any particular species, and 

 that many Euphorbia-Rowers maybe examined without detecting 

 the arrangement, whilst in others one or another part of it may 

 be very evident. It will be seen that the cymule consists of a 

 single terminal female flower surrounded by a number of males 

 arranged in four or five clusters, in two rows in each cluster, these 

 clusters representing the primary branches of the cymule ; and each 

 of these primary branches or clusters is subtended by a bract — the 

 four or five bracts united in an involucre, almost to the top in Eu- 

 phorbia, not so high in one species of Synadenium, not up to the 

 middle in CalycopepJus, and shortly and irregularly in Antho- 

 stema. Outside the involucre are usually prominent glands, cor- 

 responding to those observed at the base of the bracts on each 

 side in many Hippomanese. These glands are similarly lateral 

 and almost basal in Anthostema, though irregular and here and 

 there deficient. In Synadenium all those of the five bracts are 

 united in a single continuous ring round the base of the invo- 

 lucre. In most Euphorbice the two contiguous ones of adjoining 

 bracts are united into single, often two-lobed glands, alternating 

 with the lobes of the involucre. In a few species of the section 

 Poinsettia, and still more so in Pedilanthus, the glands become 

 very irregular, usually deficient on one side of the involucre. 

 In Calycopeplus the glands are very small or entirely disappear. 

 Inside the involucre, besides the flowers, there are in most species 

 of Euphorbia a number of narrow or hair-like scales mixed in with 

 the male flowers, or crowded between the clusters, as represented 

 in Baillon's diagram. These appear to be in exact correspon- 

 dence with the bracteoles subtending the male flowers in many 

 Euphorbiaceae ; the lower ones (those next the centre of the 

 cymule) are often more or less united at the base, especially 

 when empty, prominently united in a few species, as represented 

 in E. cascorum and E. insulana in the € Flora Brasiliensis.' In 

 Calycopeplus, Anthostema, and Synadenium these outer bracteoles 

 are united in as many broad bracts as there are clusters, each 

 completely enclosing the cluster ; and in Synadenium the five are 

 more or less united at the back into a tube surrounding the 

 pedicel of the female flower. In Baillon's view of the supposed 

 flower these bracteoles would be quite unintelligible. 



