Sessional_Paper_1905 — Page 436

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"THE SUPERFICIAL LYMPHATICS OF THE CHEST include the vessels running "under cover of, and collecting lymph from, the pectoral muscles, the cutaneous "lymphatics of this region, and the greater number of the lymphatics of the mamma. They are directed outwards and traverse the pectoral glands on their way to "join the principal axillary glands. Associated with these vessels are the super- "ficial lymphatics of the upper part of the abdominal wall, which commence "about the level of the umbilicus, where they decussate with others passing down- "wards to the superficial inguinal glands, and then ascend to the pectoral and "axillary glands.

"THE SUPERFICIAL LYMPHATICS OF THE BACK converge to the axillary glands "from its various regions; from the neck over the surface of the trapezius muscle, "from the posterior part of the deltoid, and from the whole dorsal and lumbar regions as low as the crest of the ilium; the branches decussating inferiorly with "vessels leading to the inguinal glands, and likewise crossing the middle line so as

to decussate with branches of the opposite side."

*

Now, while in spite of the conclusions come to by Dr. HUNTER, I am still inclined to attach most importance to the skin-infection theory, I do not see the necessity of assuming that given a skin infection further progress of the disease must be via the lymphatics alone, or that, when once a skin infection has occurred, the virus is carried to and entirely arrested by the nearest lymphatic glands there to set up the irritation which leads to the formation of a bubo.

A septicemia may be produced as a direct result of skin innoculation and for reasons which I give I am inclined to think that it may also occur indirectly via the lymphatics as a consequence of the normal flow of lymph and in this way earlier than if the bacilli only entered the blood stream through the degenerating blood-vessels of a bubo.

Evidence of infection through the skin has been furnished by the disease being contracted through wounds contracted during the making of post-mortein exam- inations. Also by experiments on animals it has been shewn that plague will develop when the skin is scarified and virulent matter applied to the wound. It however does not seem to me necessary that such lesions as these are required in order to get an infection through the skin. A wound contracted whilst performing a post mortem examination, or the scarification of the skin for an experimental innoculation will cause an enorinous lesion relative to those suggested as the probable channel of entrance of the virus by those who support the skin-infection. theory, namely such slight lesions as an inflamed hair follicle, a nail spring, a slight abrasion of the skin or mucous membrane, or such as might be caused by the bite of a flea or the presence of a parasite such as the itch mite (surcoptes scabei).

The supposition that the virus most frequently effects its entrance through the skin does not exclude the possibility of the infection becoming in a great many cases septicæmic at a comparatively early stage.

The circulatory system cannot be divided by a hard and fast line into a blood vascular and a lymph vascular system. The intimate connection between the two must be remembered.

It does not seem right to look ou a lymphatic gland as a perfect filter; the the structure of the glands negatives such an idea. There appears to be no reason to suppose that plague bacilli carried to a lymphatic gland by its afferent vessels may not pass through the gland into the efferent vessels.

The plague bacillus is said to produce little or no soluble toxin in fluid cultures.

The toxic effects of the bacillus are said to be due to an intracellular poison probably of a proteid nature. This poison may become free on disintegration of the bacillus.

This seems to me to have a bearing on the possible passage of the bacillus pestis into the blood stream via the lymphatics.

The lymphatic glands should not be looked on as perfect filters. Where lymph corpuscles can pass, there also could plague bacilli pass when the anatomy of the glands alone is taken into consideration, and if the toxin of the bacillus is not