1913.] The N.Z. Journal of Science and Technology. 183 
the society establish a library of microscopic slides and a representative 
entomological collection. Six members undertook to submit their collec¬ 
tions for the society to select from, and it was resolved to purchase the 
necessary slide-boxes and airtight entomological cabinet-drawers. With 
regard to the slide library it was decided that slides acquired by the 
society either by donation, purchase, or by the work of the students 
should be available for loan to members or home study, and that slides 
loaned to the society should be available for study at the society’s rooms, 
but not for removal. It is anticipated that a very valuable collection will 
be accumulated in the course of a few years. 
The following officers were nominated for the ensuing year : Presi¬ 
dent, Mr. E. E. Stark ; Secretary and Reporter, Mr. Graham ; Treasurer, 
Mr. G. P. Steel; Committee, Messrs. Campbell, Dash, Williams, and Turner. 
March 2.—The suggestion having been made that the society should 
make a systematic investigation of the entomology of the Port Hills, a. 
field excursion to McDonald’s Bush, Hoon Hay, was made, resulting in 
the capture of sixty species of insects. 
March 7.—Mr. J. H. Wilson, M.A., gave an illustrated lecture entitled 
“ The Way to His Heart,” in which he described, from a microscopical 
standpoint, the various tissues and structures forming the alimentary canal 
and the organs of absorption, assimilation, and circulation. Hints were 
given as to the preparation of some of the tissues for mounting and 
exhibition. 
Mr. J. W. Campbell exhibited a number of slides illustrating various 
parts of beetles. 
March 21.-—Mr. S. Lindsay gave a short address on “ The Evolution of 
Insects,” and Mr. Charles H. E. Graham one on “ Diatoms,” exhibiting a 
number of slides of typical diatoms from Lyttelton, Sheffield (N.Z.), Sumner, 
the Heathcote River, New Brighton, Oamaru, and other localities in New 
Zealand. 
April 4.—Mr. A. Grant gave an address on “ Micrometers.” He described 
in detail the method of constructing both “ stage ” and “ eye-piece ” 
micrometers, explained the manner of using them, and emphasized the 
necessity of microscopists being able to determine for themselves the 
magnifying-powers of the different combinations of eye-pieces and objectives 
used on their instruments. He exhibited a machine, capable of ruling 
20,000 lines to the inch, used in the manufacture of stage micrometers. 
Eye-piece micrometers were made by a photographic process, wet plates 
being used, as the grain in the film of a dry plate was too coarse. 
Mr. E. E. Stark explained the use of the camera lucida in microscopic 
measurements, the method of measuring the thickness of cover-glasses, 
and the manipulation of the vernier micrometer. He had on exhibition 
various appliances, including an automatic micrometer-ruler. 
Mr. A. Noble stated that a dry plate could be made to do all that a wet 
plate could. He was speaking from over forty years’ experience as a plate- 
maker. Such plates, however, would be very slow, and would have to be 
specially made. 
Wellington Philosophical Society. 
April 24.—Mr. R. L. Andrew delivered a lecture on “ Laboratory Con¬ 
trol of Milk-supply,” with experimental illustrations. It was shown that 
by simple butter-fat and specific-gravity estimations, occupying only a 
few minutes, the farmer or milkman could obtain a fairly accurate idea of 
the main constituents of his milk, and could see how it complied with the 
