THE VICTORIAN xNATURALIST. 103 



two fruits on one stem, collected by C. Walter at Fernshaw. 

 By Mr. G. A. Keartland. — Skin and eggs of Raven Crow {Gorvus 

 corone). By Mr. J. A. Kershaw. — Specimens of Heteronympha 

 paradelpha, Lower, taken at Bulli, New South Wales, in March, 

 1 893, by Mr.W. Kershaw (recorded for the first time out of Victoria). 



PHOTO-MICROGRAPHY. 



The following is a resume of the paper read by Mr. Frank. 

 L. Baker at the practical meeting of the Field Naturalists' Club on 

 Monday evening, 24th April, 1893 : — 



Photo-micrography is the name given to that process by which 

 the enlarged image of an object as seen through the microscope 

 can be permanently impressed upon a light sensitive surface. 



It is about fifty years since the first specimen of this work was 

 produced, and although it is yet practised only by few, and ex- 

 celled in by still fewer, the pursuit of photo-micrography is ex- 

 tending and progressing, and will doubtless have a very powerful 

 influence in the scientific education of the future. 



The many advantages obtained by this work are almost too 

 obvious to need mention. Previous to the introduction of photo- 

 micrography drawings of objects had to be made by means of the 

 camera lucida attached to the microscope — a very difficult and 

 often unsatisfactory piece of work at the best — while, of course, 

 there are many objects so fine in structure that the human hand 

 could not draw them with anything like scientific accuracy. In 

 photography, however, no line is too fine and no structure too 

 intricate to be represented in all its detail on the photographic 

 plate. Then, again, when an object has been drawn by means of 

 the camera lucida, and much time spent in producing a single 

 picture, with many imperfections, its sphere of usefulness is very 

 limited, compared with, that of a good negative, produced in less 

 time, with less labour, and from which one can print innumerable 

 copies. The photo-micrograph can be seen and appreciated by 

 those who have never looked through a microscope. Objects 

 illustrating cell structures of plants, or showing the ingeniously 

 provided spider's foot, the exquisitely delicate markings of 

 diatoms or the infinitesimally small typhoid and cholera bacilli, can 

 thus be readily and accurately shown in pictures which can pass 

 from hand to hand, educating wherever they are seen. Further- 

 more, from the photographic negative can be made a slide by 

 means of which objects otherwise invisible, except with the 

 highest powers of the microscope, can be enlarged in the optical 

 lantern to a diameter of 20 or 30 feet and shown to a large 

 audience. 



Then, again, immense improvements are being made in photo 



