1880.] 



MICROSCOPICAL JOURNAL. 



79 



MICROSCOPICAL SOCIETIES. 



LANCASTER, PA. 



The Microscopical Society of Lancaster, 

 Pa., was organized February 9th, and has 

 already reached the number to which its 

 membership wasjimited — twenty-five. In 

 addition to the business meetings, a 

 monthly " conference " will be held for 

 scientific lectures and discussions. A 

 large portion of its members are physi- 

 cians, but other professions as well as 

 trades are represented. The President, 

 Dr. J. W. Crumbaugh, delivered the 

 first lecture, on " The Microscope," on the 

 16th of March. The new Society promises 

 well and has our good wishes. 



WELLESLEY, MASS. 



The regular meeting was held Monday 

 evening. March 9th, 1880, Miss Hayes, 

 the newly elected President, in the chair. 

 The first paper by Miss Beattie, on " Cell 

 Walls," was finely illustrated by black- 

 board drawings, copied from her own 

 work, as was also the next paper by Miss 

 Cook on " Cell Contents." The remainder 

 of the evening was occupied by Miss 

 Whiting, who gave an exhibition upon the 

 screen, of crystallization. The substances 

 used were nitrate of silver, chlorides of 

 ammonium, barium, potassium, sodium, 

 calcium, sulphates of iron and copper, 

 bichromate of potash, alum and camphor. 

 Under the microscopes were shown, with 

 parabola-illumination, several crystalliza- 

 tions, and in illustration of the papers read 

 the following slides, prepared by Miss 

 Painter : Crystalloids from potato-tuber ; 

 cystoliths from leaf of Ficus elasticus ; 

 crystals from onion, calla, and leaf of 

 cactus; starch-granules from potato-tuber, 

 and milk-sap of Euphorbia ; stomata 

 from leaves of lily and begonia, and 

 cyclosis in stamens of Tradescatttia. 

 M. Virginia Smith, 



Cor. Sec. 



LIVERPOOL (ENG.) 



The third ordinary meeting of the 

 twelfth session of this Society was held at 

 the Royal Institution on Friday evening, 

 March 5th, 1880. 



Mr. Stuart, of Messrs. Ross & Co., 

 London, exhibited and explained the prin- 

 ciple of their new Patent Microscope, the 

 chief advantage of which consists in a 

 firm, thin stage and swinging substage. 



The paper of the evening was by the 

 President, Dr. J. Sibley Hicks, on " The 



Eyes of the Arthropoda." Dr. Hicks 

 briefly described the condition of the eye 

 in some of the Thysanura, pointing out 

 that in two of the Genera of that Order 

 the eyes consist only of dark pigment. 

 After describing the conglomerate eye as 

 seen in the common Millipeda, he pro- 

 ceeded to give a more detailed account of 

 the eyes of Spiders. He showed that the 

 disposition of the eyes in these harmless 

 and much despised little creatures,although 

 uniformly symmetrical, is extremely varied. 

 Referring to their color and structure, he 

 described the eyes of some spiders as 

 being of the most brilliant hues ; each 

 eye a brilliant little shining hemisphere, 

 and the tiny cluster of eyes grouped in 

 front of the head in some of the Salticides, 

 sparkling and glistening like polished 

 gems, vying in color and lustre with the 

 emerald and other precious stones. The 

 structure of these eyes, although in a 

 somewhat rudimentary condition, is the 

 same as that which exists in the higher 

 animals. The most important part of the 

 paper was that which referred to the com- 

 pound eye which belongs alike to the 

 insect and crustacean. These animals 

 have two compound eyes placed one on 

 each side of the head, and each of these 

 eyes, when examined under a low power, 

 is seen to be diyided into numerous 

 facets which, in some instances are square, 

 and in others hexagonal. The eye of the 

 common house-fly has as many as 4,000 

 of these facets, and in some beetles the 

 number is as large as 25,000. Dr. 

 Hicks proceeded to minutely describe the 

 internal structure of these compound eyes, 

 showing that they are composed of num- 

 bers of cones and rods closely packed 

 together, each rod and cone corresponding 

 to a facet. Dr. Hicks combated the state- 

 ment which is so frequently made in books 

 that each of these facets represented a 

 distinct eye, maintaining that such state- 

 ments were not in accordance with recent 

 microscopic investigation. After referring 

 to the manner in which the retina of the 

 higher animals is developed, he said no 

 one could fail to be struck with the simil- 

 arity and agreement in the fundamental 

 plan of structure that exists between the 

 layer of rods and cones of the retina 

 (Jacob's membrane) and the arthropod 

 eye. He showed by a series of diagrams 

 the rods and cones of the fish, the bird, ' 

 the amphibian, and the mammal, the 

 similarity between these structures and 

 the rods and cones of the compound eye 

 being very striking. To his mind there 



