could have made such a mistake, as the one which I am credited with by this Professor. However, here is my drawing of the specimen, and here is Prof. Budge's inference from my drawing of the appearance of the specimen which he has never seen, and I now pass round the preparation itself, which was made seven years ago (5). It is magnified 215. You will see the blue injection amongst the cells in the tubes, and not the faintest indication of the tubes around each cell, which Prof. Budge states he has seen, and feels convinced exist in this specimen. I hope to have the pleasure of affording to Prof. Budge some day a similar opportunity of comparing the specimen with the drawing.*

No. 6 is a corresponding preparation from the human liver magnified 130, showing the ducts just at the edge of a lobule, and their continuity with the tubes of the cell-containing network.

No. 7 is also from the human liver, and shows the capillaries injected blue, and the cell-containing-network alternating with them, and having in all parts of the lobule exceedingly thin walls, but quite distinct from the capillaries. This preparation is magnified 215.

Perhaps, however, the most perfect demonstration of the cell-containing-network, and its continuity with the ducts is obtained from the examination of the liver in cirrhosis, in which disease the cells and tubes shrink, the change commencing at the portal aspect or circumference of the lobule, and proceeding gradually towards the centre.

No. 8 is a section of a healthy liver under an inch object glass. The portal vein was injected with carmine, and the hepatic vein with Prussian blue. The capillaries of the lobule are filled with the colouring matter-those in the centre of

* I have made many injections with the chromate of lead and every other opaque injection I could lay my hands on, and have stated that I always failed. Professor Budge does not seem to have tried the plan which I employed for preparing my own specimens.

each lobule being blue, while those at the circumference are red. Observe how very narrow the interlobular fissures are, and how in many places the capillaries of one lobule are continuous with those of adjacent lobules. The interlobular spaces are clearly destitute of any areolar or fibrous tissue. They are occupied by the branches of the portal vein which you see, and branches of the artery and duct, and lymphatics, which have not been injected in this specimen. Let this specimen be compared with the cirrhose liver (No. 9), in which the vessels have been also injected. What a wide space exists between the contiguous lobules, of which but very little, and only of the central part of the lobule, remains in many cases. Vessels and tubes, which will be seen more distinctly in another specimen, are observed in the substance of the tissue usually stated to be fibrous.

No. 10 is a specimen of a cirrhose liver, magnified 130, soaked in carmine, and now you can see the shrivelled cells within the narrowed tubes, and the network so distinctly, that you will hardly fail to wonder how it has happened that the nature of this so-called fibrous tissue had not been made out long since-but many of the most delicate and beautiful textures appear fibrous enough when placed in water and roughly examined, and thus morbid changes have been supposed to originate in a really passive structure, the areolar or connective tissue.

No. 11 is a specimen from the same liver put up in water, and not a vestige of anything but 'fibrous tissue' is to be seen where we now know numerous tubes and cells and vessels are actually to be demonstrated. By immersing a delicate preparation in water, I can often produce the appearance of the presence of a large quantity of fibrous or connective tissue.

These specimens will, I think, serve to satisfy you of the great importance of preparing tissues, for I have clearly proved that many structures ordinarily invisible may be demonstrated

most distinctly by certain special processes. I might have taken illustrations from almost any other tissues of the higher animals, or from the lower animals or plants, but I have chosen those which seemed to bear most directly upon that department of microscopical enquiry, which is of the greatest interest to us as practitioners of medicine.

LECTURE II.

Of the Structure of the simplest Living Beings.

MR. PRESIDENT AND GENTLEMEN,

LET me suppose a physician, with plenty of time at his disposal, who had a love for work, and was anxious to study the nature of any disease. Such a man would continually feel desirous of ascertaining the actual changes which are going on in the organisms of his patients while they were under observation. He would very soon find that it was absolutely necessary to work at physiology and pathology, or he would not feel in a position to prosecute any special enquiry. Now he would find the greatest difficulty in coming to anything like a conclusion with regard to questions which clearly must be positively settled before he could proceed. He would thus be driven to work at the minute anatomy and chemistry of textures in disease, and soon he would discover that many fundamental questions of mere anatomical demonstration had not been determined, and the most conflicting views as to the order of growth of textures and their action, would prevent him from feeling any confidence in his work. Next he appeals to the healthy structures, and now he is dismayed at finding that we

are not sure how nerves terminate in various tissues, and, while in chemistry he finds the indefinite term 'extractive matters' applied to a considerable quantity of matter, of the nature of which he can learn very little, so in anatomy he hears of areolar or fibrous tissue, or indeterminate tissue, existing everywhere, and especially abundant in the very situations in which he would expect to find nothing unnecessary, and the arrangement of the tissues of the most beautiful character, according with the wonderful delicacy of the offices to which he knows them to be subservient. He looks for some general explanation of the appearances he sees, and he finds cells described in works, and delineated with most distinct cell-walls, contents, and nuclei, but when he comes to examine the tissues, it is but seldom he detects anything answering to the ordinary description of a cell, and with respect to so simple a structure as cartilage, he can scarcely find any two observers who agree as to the meaning of the appearances observed.

He enquires how a tissue grows; which is the oldest part, and which the youngest ?-how food becomes tissue?—where inanimate matter becomes living ?—what is actually living, and growing, and changing, and what has ceased to live and change, and has grown to its full dimensions? Every one who has thought earnestly on medicine during the last few years, must have frequently asked himself these questions.

Let us suppose such questions now asked, and before we proceed further in the enquiry, and in order that we may get them answered in the simplest and clearest manner, let us appeal in the first instance to one of the simplest living structures we are acquainted with,-common mildew. I have described at some length the changes taking place in this structure, and propose now to refer very briefly to the results.* We shall afterwards be able to discuss with better chance of success the general anatomy of the tissues of the higher animals, and we shall be able to examine the cell theory and other Archives of Medicine, No. VII, page 179.