346 PROCEEDIXGS OF THE 



clump, the individuals of that clump will not be very much larger 

 or smaller than those before you." Attention was directed to the 

 small closed orifice at the top, resembling a tiny mouth with 

 closed lips. They were rare plants, three of them undescribed and 

 unnamed species at present. The audience were invited to give 

 the name of the genus, or even of the order to which they 

 belonged, if able, but no one seemed inclined to attempt this. 

 Mr. Brown was not surprised, and remarked that " when the first 

 species of this group was described and figured in 1738, its dis- 

 coverer, Johannes Burmann, Professor of Botany at Amsterdam, 

 mistook it for one of the puff-ball fungi." Mr. Brown said he 

 wished to show some of the stages that seemed clearly to indi- 

 cate the connection of the simple forms seen in the pot before 

 them with other forms that appear to have no resemblance what- 

 ever to these. " The divergence of the species of this genus 

 is very great and remarkable. To start with, we have humble 

 and simple plants like those shown, and radiating from them as 

 an initial stage are many lines of development — one line cul- 

 ^linating in a shrub 15 ft. high, another ending in a herb with 

 a loose tuft of a few erect leaves as large as those of a lettuce, 

 and trailing flowering stems two or three feet long and an inch 

 thick. Yet the flowers throughout the genus vary very little 

 except in size and colour. The genus is Mesembryanthemum, 

 commonly called ice-plants. This particular group of the genus 

 is one of the most remarkable at present living, and has two 

 special points of interest : — (1) With the exception of the 

 members of the order Rafflesiaceae, in their vegetative organs 

 they are the most primitive and simple of all Dicotyledons, and 

 quite unlike any others in existence ; (2) the peculiar manner of 

 their growth, which seems utterly unlike that of any others, and 

 yet, when critically examined, is found to follow the same 

 general rule as other flowering plants. It is a recognised fact 

 that, however widely adult organisms may differ, yet in their 

 embryonic stage they are often similar. AVe note that when we 

 sow seeds belonging to a great variety of plants belonging to 

 different orders, when the seedlings first appear there is often 

 a great similarity in their form." This is the case in the seedling 

 stage of Mesembryanthemum, but in the group to which those 

 shown in the pot belong, the seedlings are reduced to the most 

 primitive condition possible. ''In most cases, as the pliuit 



