106 OEIGIN OF COLORED BLOOD-CORPUSCLES. 



going on in the adenoid tissues. His conclusions are that the corpuscles have 

 sprung up de novo from the blastema, and by analogy he argues that there is 

 a spontaneous generation going on in serum wherever it is found. As given by 

 Flint, these experiments on animals are as follows : The serum from quickly 

 drawn blisters, after having been freed by nitration, etc., etc., from all its 

 organized elements, is placed in bags of gold-beater's skin. These sacks are 

 then placed in the subcutaneous tissues of rabbits, and after a sojourn of two 

 or three days their serum is found to contain a variable number of leucocytes. 

 I have repeated these investigations, and in two directions have pushed them 

 farther than their author ; that is, instead of the blastema, in the course 

 of the experiments I used four different liquids, and in all cases, besides the 

 fluids, I examined the gold-beater's skin after its removal. 



In addition to the serum, I used a weak solution of chloride of sodium in 

 water, a mixture of this with the white of an egg, and lastly the clear part of 

 the egg alone. The animals used were cats ; the length of experiments from 

 seventeen to fifty hours ; the thickness of the inclosing membranes was in 

 most instances one, but in two cases two, layers of the gold-beater's skin. In 

 all cases I examined both membrane and blastema before the introduction to 

 the cat, and thus made sure that no organisms were present. My results were 

 that in every case, except where I used a varnished membrane, I found leu- 

 cocytes in the blastema, and wherever they were found in the liquid, the 

 walls of the inclosing bag were sure to be crowded with the same organisms. 



The only things that seemed to influence the number of the corpuscles 

 were the condition of the containing membrane and the length of time the 

 sack remained under the skin. If these conditions were the same, there were 

 just as many corpuscles in the solution of chloride of sodium, or the egg mixt- 

 ures, as there were in the serum. In the cases where the skin was doubled 

 after a longer time than was ordinarily employed, a few corpuscles made their 

 appearance in the blastema, a few were found in the inner layer of the bag, 

 whilst the outer one contained a great many. 



From these facts we are forced to the conclusion that the corpuscles 

 migrated through the walls of the bags, just as they do to the interior of the 

 catgut ligatures that are left in similar conditions. 



This, however, is only a negative kind of proof, and for something positive 

 I will ask the reader's attention to my recent study of the so-called adenoid 

 tissue. 



It is not necessary here for me to give the histology of the organs that 

 contain this tissue, and to repeat that in the lymph-ganglia it is arranged into 

 lymph follicles, lymph cords, and interfollieular strings ; in the alimentary 

 canal into follicles such as are contained by the tonsil, base of the tongue, 

 pharynx, stomach, solitary glands, Peyer's patches, etc. ; in the spleen into 

 the ensheathing coats of the arteries, and the so-called Malpighian corpuscles, 

 etc. But for our purpose, all that we need to know is that, wherever this 

 tissue may be, there is a stream of fluid coming into it on one side, which, 

 after working its way through the sponge-like mass, passes out on the other, 

 and eventually empties into the blood. 



The two questions to which we will now address ourselves are : Whence 

 comes and what is the function of the " adenoid" tissue. 



All histologists agree that in the animal kingdom we find but four 

 varieties of connective tissue, and that they are the myxomatous, the fibrous, 

 the cartilaginous, and the osseous. The myxomatous connective tissue is met 



