59 



skins and birds' eggs. The donor writes to say the birds sent have not 

 been chosen for their brightness of plumage, but he selected those not 

 likely to be obtained from other sources. Many of them are from nearly 

 200 miles in the interior. 



ON THE PRESERVATION AND MOUNTING OF AQUATIC LARV^ OF INSECTS. 

 ARTHUR WALKER. 



The object in the study of these larvae is to preserve them so as to 

 cause as little contraction as possible, and retain the internal structure and 

 external appendages intact. To obtain these results the following method 

 was recommended and demonstrated on Coretha plumicornis : — Take 

 freshly collected larvae and place them in 1-3 per cent, solution of chromic 

 acid for three days. The structure is then fixed, and without any of the 

 parts being displaced. It is then necessary to remove all loose chromic 

 acid. This is done by placing the larvae in equal parts of methylated 

 alcohol and water for twenty-four hours. Then change into two parts- 

 methylated alcohol one part, and water also— for twenty-four hours, 

 afterwards into methylated alcohol, where they are then preserved ready 

 for use, and can be studied during the winter months when living 

 specimens cannot be obtained. The method for making microscopical 

 preparations of the larvae was next recommended as follows : — Select the 

 specimens to be mounted out of the methylated alcohol and place into 

 absolute alcohol to dehydrate there— to remain in a few minutes. Then 

 pass into oil of cloves ; afterwards mount in Canada balsam. The 

 methods were practically shown and the preparation mounted at the 

 meeting examined under the microscope, along with several others treated 

 in a similar manner. It was pointed out that this method was not by 

 any means confined to the preservation of aquatic larvae of insects, but 

 answers equally well for lepidopterous larvae, &c., intended for anatomical 

 study. The success of the methods were readily apparent from the slides 

 shown under the microscope of Coretha plumicornis, an organism of very 

 delicate and contractible structure. Preparation of whole larva? of 

 simulium were exhibited, also parts and stained sections showing the 

 internal structures perfectly intact. 



Exhibits : — 

 Mr. W. Kirkby : — Giant PufFball {Lijcoperdon giganteum). 

 Mr. J. Phillips : — Double stained section of Ruscus aculeatus. 



Meeting held in the Library of the Philosophical Hall, October 6th, 

 1890, H. Bendelack Hewetson, M.E.C.S., F.L.S., in the chair. 



The Australian birds' skins and eggs presented to the Club by Mr. G. 

 A. Keartland, of Melbourne, were exhibited. The skins, about 28 in 

 number, are excellently preserved, and form a valuable collection. The 



