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animals living leucocytes might be seen at the ordinary temperature of the at- 

 mosphere. In making these experiments, Dr. Burdon Sanderson recommended 

 that putty cells should be employed; they were easily made, and by placing the 

 drop of blood to be examined on a thin glass cover, and inverting it so that 

 the drop may hang into the cavity of the cell, a perfectly air-tight compart- 

 ment was formed, which pi*e vented any evaporation from taking place, and the 

 blood might be watched for some hours in a living condition. Although the 

 blood of the newt coagulates immediately on touching a foreign body, this does 

 not interfere with the movements of the white blood corpuscles. Those little 

 bodies exhibit some very curious properties. They could be seen moving 

 across the stage by means of the pseudo-podia referred to, just as the arna3ba do. 

 One of the most remarkable facts about them is that they make their way out 

 of the current of the blood through the walls of the blood vessels, and wander, 

 as it were, amongst the tissues. A curious experiment made by Cohnheim 

 proved this. If the swim bladder of a fish be filled with a solution of common 

 salt, containing one per cent, of salt, tied and inserted under the skin of a 

 rabbit or frog, after a short time, say twelve or twenty-four hours, it would be 

 found filled by a large number of leucocytes, which had found their way into the 

 bladder by permeating its walls. These were alive when they left the living 

 tissue of the animal, but after going through the bladder their movements no 

 longer continued, as they died in the saline solution ; hence they were unable 

 to escape from the bladder, and a large number become entrapped. This result 

 not only applies to the swim bladder of the fish, for according to Cohnheim, if 

 the cornea of a frog's eye be taken (it must be quite fresh) and inserted under 

 the skin of a living frog, in the course of 24 or 48 hours it will be found upon 

 examination to contain a large number of leucocytes at various depths in the 

 tissue of the cornea. Mr. Lowne considered these to be very remarkable pro- 

 perties, and he laid much stress upon them as throwing a great deal of light 

 upon the doctrine of Pangenesis, as enunciated by Charles Darwin — to which 

 he had drawn the attention of the Club some time sioce— by which doctrine it 

 was supposed that particles or gemmules were given off from every part of the 

 organism, capable of reproducing like parts under certain conditions, and of 

 being collected in the ovum. The whole animal was thus permeated by particles 

 passing off from the living tissue. It had been objected by the President that 

 these particles, being solid, could not pass through the walls of a living cell ; but 

 if leucocytes could pass through solid tissues he could not see why minute gem- 

 mules, which might be solid or semi-solid, like leucocytes, should not pass 

 through cell walls. He could not see why there should be any serious objection 

 to the doctrine of Pangenesis. There was great difficulty in distinguishing a 

 solid from a fluid. If the protozoa be examined many of them would be found 

 to exhibit a series of gradations of solid matter, harder externally and softer 

 internally ; but no lines of demarcation could be drawn between the solid and 

 more fluid parts of those animals ; as one portion of the protoplasm shaded in- 

 sensibly off into another. 



The President said he wished to correct any misapprehension that may have 

 arisen with regard to some arguments which had been advanced by him in con- 

 nection with the subject under discussion at the last meeting, and had been 

 just referred to by his friend Mr. Lowne, who had suggested that because the 

 white blood corpuscles could pass through the walls of the blood vessels there 

 could be no objection to the idea that small particles of living matter (from the 

 so-called nucleus) might pass through the walls of every cell in every part of the 



