The President inquired if Dr. Dixon found that glycerine would do as well as castor-oil with the Wenham illuminator. Dr. Dixon thought that glycerine would not answer the purpose so well. The greater viscidity of castor-oil allowed a greater range of focus; and for the same reason it would not so readily run off the face of the illuminator. Mr. Stephenson said he had tried this and other immersion plans of illumination, and had resolved without difficulty Amphipleura and other difficult diatoms in balsam. He thought the fact was very often overlooked, that with a dry condenser of the widest angle it was hardly possible to resolve the fine lines of balsam objects; but with an immersion condenser it would be quite possible; and he might say that the resolving power of a Zeiss's immersion objective would be at least 10 per cent. greater on a balsam object than that of a dry lens of 180° on an object in air. Mr. T. Curties said that Mr. West, who had been very successful in producing Lissajou's curves microscopically upon glass, was present, and had brought some specimens, which were exhibited under microscopes in the room. of Mr. West said that most persons were familiar with these curves as drawn upon paper, so that he need say very little in the way describing them. He had been successful in drawing them upon glass upon a very small scale, and he was told that they possessed some value as test objects. He believed he owed much of the success to the excellence of the diamond point which had been supplied to him by Messrs. Beck. The appearance of solidity in many of the figures had attracted attention, and was rather curious. The chief difficulty in exhibiting these objects was in obtaining a proper kind of illumination. In reply to a question from the President, Mr. West stated that these figures were drawn directly upon the glass. The President said that, in returning to the old practice of having tea and coffee at the close of their meetings, they hoped to somewhat increase their social character, and for this purpose they should endeavour to get the business of the evening over by nine o'clock, so as to leave a little time afterwards for conversation and the exhibition of any objects which might be brought by any of the Fellows. He hoped, therefore, that if any Fellow of the Society had objects which he wished to exhibit or to ask questions about, he would bring them down to the meetings. At their scientific evenings they should adhere to the plan which they had found to work so well-that of bringing objects of special interest which could not be seen elsewhere; but the field of research was so great, that it was quite likely that a person well acquainted with one particular branch might find objects of another kind which were unfamiliar to him, and about which he might be glad to have the opinions of others at the ordinary meetings. The following gentlemen were elected Fellows of the Society, viz.-John Davis, Esq.; George Raynor, Esq.; Francis Boughton Kyngdon, Esq.; and the Rev. G. E. Watts, M.A. KING'S COLLEGE, April 3, 1878. H. J. Slack, Esq., President, in the chair. The minutes of the preceding meeting were read and confirmed. The list of donations was announced, and the thanks of the Society returned to the respective donors. The President gave notice that upon the recommendation of Mr. Stephenson, Dr. Matthews, and Mr. Crisp, in accordance with the fifteenth bye-law, and with the approval of the Council, Professor Abbe, of Jena, had been duly nominated an Honorary Fellow of the Society, and that accordingly the Professor's name would be suspended in the usual way and submitted for election at the meeting of the Society in May. Mr. J. W. Stephenson read a paper "On a New Large-angled Immersion Objective without any Adjustment Collar." The President said that Mr. Stephenson had been kind enough to bring down to the meeting the object-glass which he had described in his paper, and another of the same pattern belonging to Mr. Crisp was also in the room, and it would be, no doubt, interesting and useful to examine them after the meeting. Mr. Frank Crisp said that he could bear testimony to two, at any rate, of the advantages of the new objective, viz. the great increase of light, and the facility with which it could be at once adjusted to the object, being without correction collar. It might be interesting to observe, by way of history, that the use of oil in Mr. Stephenson's objective had nothing in common with the use of it for microscopical purposes by Sir David Brewster in 1810-before the application of achromatism to the microscope. His plan was to place the object to be observed at the bottom of a small glass cylinder filled with oil, and the objective was focussed upon the object through the oil. There was thus a convex lens of crown glass, and the oil acted as a concave lens. If the proper curves were taken for the convex lens, there would in the result be (theoretically) an achromatic combination. Dr. Matthews thought that the discrepancy observed as to the tables of refractive indices, to which allusion had been made in the paper, might be due to the age of the oil. All essential oils underwent oxidation, which caused them to become thicker and more refractive, and this might account for the discrepancy. The President inquired which of the essential oils was least subject to this kind of alteration. Dr. Matthews was hardly prepared to say without looking into the subject more closely, but he believed the worst was turpentine. The President said it was clear that the chief consideration in the case of this objective was to get the proper kind of oil. The thanks of the meeting were voted to Mr. Stephenson for his paper. Mr. Frank Crisp read a paper "On the Present Condition of Microscopy in England." The President thought that Mr. Crisp had hardly been quite fair to Dr. Pigott in the course of his observations. Dr. Pigott only wanted to prove that the best object-glasses had some small but important residual error, and could be improved by the use of the means which he proposed. The thanks of the Society were voted to Mr. Crisp for his paper. The President announced that they had received two pamphlets on diatoms from Professor Cleve, and that a number of specimens in illustration had been sent for examination. Dr. Millar had also brought with him a singularly beautiful species of sponge, Acarnus innominatus Gray, and Mr. Curties exhibited a number of specimens of stained tissues. Donations to the Library since February 6, 1878: 1876 and 1877 .. Journals of the Linnean Society Proceedings of the Literary and Philosophical Society of Liverpool, Brooke's Introduction to Crystallography Catalogue and Description of the Rarities belonging to the Royal Society. By N. Grew, M.D., 1681 Amphitheatrum Zootomicum. By M. Bernardo Valentine, 1720 The Microscopist. By Dr. J. Wythes, 1853 Dialogues on the Microscope. By Rev. J. Joyce Two Papers on Diatoms from the Arctic Sea. By Prof. P. S. Cleve Ditto. Society. Ditto. Ditto. Ditto. Editor. Society. Ditto. F. Crisp, Esq. Ditto. Ditto. Ditto. Ditto. Author. John Naish Smart, Esq., and Thomas Bolton, Esq., were elected Fellows of the Society. WALTER W. REEVES, Assist.-Secretary. JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY. JULY, 1878. I.—The Structure of the Coloured Blood-corpuscles of Amphiuma tridactylum, the Frog, and Man. By Dr. H. D. SCHMIDT, Pathologist of the Charity Hospital, New Orleans, La. (Taken as read before the ROYAL MICROSCOPICAL SOCIETY, April 3, 1878.) PLATE V. (Continued from p. 78.) BEFORE further discussing in detail the observations relating to the structure of the coloured blood-corpuscles of the Amphiuma, I propose to give a brief description of the mode of their development from the colourless corpuscles. Their origin, or original development in the first stages of embryonic life, I had no opportunity to observe; for in those embryos which I fortunately obtained they were already completely formed. As we may suppose that the metamorphosis of a colourless blood-corpuscle into a coloured one is not accomplished in a space EXPLANATION OF PLATE V. FIG. 28.-Coloured blood-corpuscle of Amphiuma, treated with a 2 per cent. solution of boracic acid. FIG. 29.-Coloured blood-corpuscle of Amphiuma, treated with the vapour of a 4 per cent. solution of osmic acid. Figs. 30, 31, 32, and 33.-Coloured blood-corpuscles of Amphiuma, treated with a strong solution of hydrate of chloral. FIG. 34.-Coloured blood-corpuscle of Amphiuma, treated with nitric acid vapour. FIG. 35.-Coloured blood-corpuscle of Amphiuma, treated with nitric acid liquid. FIGS. 36 and 37.-Coloured blood-corpuscles of Amphiuma, treated with diluted nitric acid. FIG. 38.-Coloured blood-corpuscle of Amphiuma, treated with ether liquid. FIG. 39.-Colourless blood-corpuscles of adult Amphiuma. FIG. 40.-Different forms of transition from the colourless into the coloured blood-corpuscles, met with in the blood of adult Amphiuma. FIG. 41.-Colourless blood-corpuscles from the pulp of the spleen of adult Amphiuma. FIG. 42.-Colourless blood-corpuscles and their transitory forms into the coloured corpuscles, met with in the blood of the very young Amphiuma. VOL. I. [FIG. 43. I of time short enough for any observer to witness it under the microscope, the process of development or transition can only be studied by making certain deductions from the various transitory forms of these blood-corpuscles as they are met with in the blood of the animal. In the blood of the adult animal, the primary form of the colourless blood-corpuscle seems to be a nucleus surrounded by a layer of granular protoplasm (Fig. 39, a). The nucleus represents a vesicle, distinguished by a distinct double contour, and containing a limited number of granules. Both contour and granules show a faintly greenish tint. The multiplication of the corpuscle takes place by a division of the nucleus, while it is still surrounded by the protoplasm (Fig. 39, a and b), though many instances are observed where the nuclei are set free by the dissolution of the protoplasm (Fig. 39, c), and hence a number of free nuclei are always met with in the blood. The transitory forms to be studied are represented in Fig. 40. The first (a) is a round nucleus, in which the inner contour of its wall is represented by a zone of minute granules of a greenish tint, appearing as if deposited upon the inner surface of the wall; in the interior of the body the usual granules are observed. The second form (b) represents a larger FIG. 43.-Coloured blood-corpuscle of the young Amphiuma. FIG. 44.-Coloured blood-corpuscle with its protoplasm contracted, from the young Amphiuma. FIG. 45.-Egg of the Amphiuma with embryo (natural size). FIG. 47. The same, slightly enlarged. FIG. 48.-Coloured blood-corpuscles of the large Bull-frog; a, front view; b, side view. FIG. 49.-A coloured blood-corpuscle of the same animal, in which a retraction of the protoplasm has taken place, exposing the membraneous layer. FIG. 50.-Coloured blood-corpuscle of the Frog, with spinous elevations on its surface. FIG. 51.-Coloured blood-corpuscles of the Frog, treated with water. FIG. 52.-One of the same, treated subsequently with a weak solution of chromic acid. FIG. 53. Coloured blood-corpuscle of the Frog, treated with acetic acid vapour. FIG. 54.-Coloured blood-corpuscles of the Frog, treated with a weak solution of chromic acid. FIG. 55.-Coloured blood-corpuscles of the Frog, treated with a strong solution of hydrate of chloral. FIG. 56.-Coloured blood-corpuscles of the Tree-frog; a, front view; b, side view; c, one with a portion wanting, as described in the text. FIG. 57.-Coloured blood-corpuscles of the Tree-frog, treated with a weak solution of chromic acid; a, corpuscle with the protoplasm contracted in the form of a star; b, the protoplasm entirely contracted upon the nucleus; c, granular appearance of the protoplasm. FIG. 58.-Infusorium found in the blood of the Tree-frog. FIG. 59.-Coloured blood-corpuscles of Man; a, front view; b, side view. FIG. 60.-Various forms of coloured blood-corpuscles of Man, produced by a partial contraction of the protoplasm. FIG. 61.-Coloured blood-corpuscles of Man, exhibiting spontaneous motion. FIG. 62.-Coloured blood-corpuscles of Man, treated with water. |