258 ARTHUR WILLIAM MEYER 



SO as to remind one of the spleen, because of the accumulation of 

 erythrocytes which lay free in the reticulum among the lympho- 

 cytes, believed that this was the result of diapedesis after splen- 

 ectomy. Tizzoni, however, as quoted above, regarded the changes 

 in lymph nodes due to a lympho-adenitis resulting from a simple 

 traumatic irritation. 



In view of Meek's observations and conclusions a series of 

 experiments were also undertaken on five guinea-pigs of known 

 weight. One was given repeated injections of distilled water, 

 the other of oxalic acid and three of diphtheria toxin. The 

 injections were made directly into the peritoneal cavity. The 

 amounts injected and the strengths as well as all other necessary 

 data are given in table 2. 



From the table it will be seen that hemal nodes were not found 

 in a single instance. In case of no. 5 which died one week after 

 the injection of 5/7 T the peritoneal cavity contained 1 to 2 cc. 

 of bloody exudate but no hemal nodes had formed. The lymph 

 nodes were difficult to recognize and only a single large lymph 

 node at the root of the mesentery was slightly reddened. On 

 injecting this node the usual results were obtained. The same 

 statement holds for guinea-pig 4 which succumbed one day after 

 the third injection of 1 cc. of a 1 per cent oxalic acid solution, 

 and also for all the other animals. 



Since as Retterer (29) showed, it is not uncommon to find 

 more or less reddish lymph nodes in entirely normal guinea-pigs 

 of all ages, under various conditions, and from many injections 

 made on such, I am compelled to conclude that the above experi- 

 ments did not result in the production of hemal nodes nor did 

 they produce any unusual color changes in the lymph nodes. 

 Hence from a review of the literature and from the experimental 

 evidence available the conclusion that up to the present, no one 

 has offered sufficiently conclusive evidence for the experimental 

 production of true hemal nodes — not hemorrhagic lymph nodes — 

 and accessory spleens is unavoidable. However, since true he- 

 mal nodes would seem to appear and disappear for some unknown 

 reason the 'possibility of their experimental production — and that 

 of supernumerary spleens? — is not denied. Changes in l;yTxiph 



