1 53 
on the Biology of Roridula. 
fall, I noticed a spider walking about on the bushes, and on 
examining the bushes more closely I found that the spiders 
were quite numerous. They were all of one kind, belonging to 
the genus Synaema 1 (Crab-spiders). Dr. Purcell, who kindly 
examined the specimens, is of the opinion that it is an un- 
described species. The crab-spiders spin no web, but wait for 
their prey and pounce upon it whenever it comes near enough. 
This species had selected the Roridula for its residence, and 
was evidently quite at home there, for numerous little nests 
were hidden among the leaves, some of which were empty and 
serving only as hiding-places for the spiders, while others 
contained a large number of young spiders. 
The surprising feature of the matter was, that the spiders 
were able to walk or run over the leaves without the slightest 
hindrance from the sticky secretion of the tentacles. When- 
ever an insect was caught by a leaf and began to hum or 
to struggle, a spider in its neighbourhood would dart from its 
nest and secure the prey. Hence it is evident that the spider 
must be protected by some kind of varnish or grease against 
the sticky fluid, for neither their legs nor their bodies 
adhere to it in the slightest degree. Whether the same 
species of spider lives on any other plant is not known, but it 
has evidently adapted itself to the Roridida , and lives on the 
insects caught by the bush. 
As the R. dentata grows also in the Cedarbergen and the 
Cold Bokkeveld I have endeavoured to obtain some fresh 
material from those regions, in order to ascertain whether 
the spider occurs there as well, but owing to the disturbed 
state of the country I have not been successful as yet. 
The other species of Roridula , viz. R. Gorgonias , was for 
a long time only known to occur on the mountains of the 
river Zonder Ende, but recently Dr. Stoneman had found it 
in the valley of the Steenbrass river. When I visited this 
locality last February, I found the greater part of the valley 
burnt out, but finally succeeded in discovering a small patch 
of the plant. There were no spiders or spiders’ nests on them, 
1 Nature, vol. lviii, 1898, p. 275. 
