Page:Supplement to harvesting ants and trap-door spiders (IA supplementtoharv00mogg).pdf/51

 differ from those of its competitors; for we may be quite certain that it does not exist where we see it by grace and favour, but by merit; if it is neither stronger, cleverer nor more numerous than its neighbours, we may be sure that it has found some means of living which does not interfere fatally with their requirements. Hence the endless diversity of function and habits in all living creatures, which forms such a prolific and marvellous subject for our study and contemplation.

I am indebted to M. Simon for permission to publish the details given above on ''Cyrtauchenius elongatus'', and also for having given me such directions as enabled me to make the sketch from which the drawing at Plate XIII., fig. B, was copied.

I must however state that this illustration is not taken from an actual specimen, but is prepared solely from his description; so that it cannot pretend to complete accuracy of detail. M. Simon assured me nevertheless that it conveyed the general appearance of this remarkable nest with sufficient fidelity, and I have been induced to reproduce it here in the hope that it may serve to make my meaning plainer, and to suggest the kind of object which one should look for, if an opportunity offered.

Another species of the same genus, ''Cyrtauchenius Doleschallii'', is known to inhabit Sicily, but the nest is undescribed. M. Lucas has described two species, belonging to the closely-allied genus Cyrtocephalus, both of which appear to construct nests somewhat similar in form to that discovered by M. Simon.