1898] NOTES AND COMMENTS 301 



which should be referred to the family Forficulidae. Though this 

 view met with strong opposition at the time, it is now proved to be 

 entirely true. Since his return to Ceylon, Mr Green has studied 

 pretty completely the life-histories of the insects in question, and in 

 the paper referred to has communicated the results of his investiga- 

 tions. He has shewn that the long-tailed larvae become transformed 

 into ordinary-looking earwigs, each provided with the orthodox pair 

 of pincers. The segmented tails are retained by the larvae up to 

 the final moult preceding the change to the imago. They then dis- 

 appear, with the exception of the long basal segment of each tail. 

 The pincers of the imago may be seen formed within these basal 

 segments, and Mr Green is of opinion that the pincers represent the 

 basal segments only of the larval tails. Mr Gahan, however, con- 

 sidered it more probable that the whole interior substance of each 

 tail was contracted within the basal segment, and there became 

 changed into the pincer, in support of which view he mentioned the 

 fact, noted by himself, that traces of segmentation might be observed 

 in the pincers of the common earwig at a stage just preceding the 

 exclusion of the embryo from the shell. 



Photography in Geology 



In our March number we alluded to the work being done in collect- 

 ing photographs illustrative of British Geology. It is no doubt a fact 

 that the prints receive house-room at the Museum of Practical 

 Geology, but the actual work is one carried out by private indi- 

 viduals. The April number of the Fliotogram gives a very interest- 

 ing account of the photographic work in connection with the U.S. 

 Geological Survey. We have, in this country, various scientific 

 institutions under Government, which appear to make far less use of 

 photography than might be expected; but this is a subject to which our 

 opportunities of returning will be perennial. At present we content 

 ourselves with quoting some of the paragraphs from the Photogram. 

 " The official photographer of the Survey, J. K. Hilliers, who is 

 responsible for the work of a very great number of field photo- 

 graphers, and also of a considerable in-door staff, is entirely a self- 

 taught man, who originally joined one of the geological parties as a 

 baggage packer. Assisting the photographer attached to the party, 

 he gradually picked up the methods of working, and, when the 

 photographer died, was able to continue his duties. Prom this time 

 he always remained a photographer, gradually rising in the service, 

 until with the increase of the service itself, he has now a very 

 responsible position. His work shows that he is a photographic 

 genius, as well as a good deal of an artist, as our readers will have 

 an opportunity of proving for themselves at the Paris Exhibition of 

 1900. For this exhibition the Geological Survey is preparing a 



