516 Chapter XVI 



views on immunity, although this subject was not discussed at all in 

 his pamphlet. He expresses himself thus : " The immunity of animals 

 and plants in complete health depends in my opinion : (1) on the 

 relative quantity of salt contained in their fluids, and (2) on the 

 property of their contractile cells of ingesting the enemy which enters 

 the animal body " (p. 18). As these statements have been put forth 

 without receiving any further development, in the midst of all kinds 

 of other speculations, it is not astonishing that the words I have just 

 quoted, as well as Roser's pamphlet itself, should not have attracted 

 the attention of either zoologists or medical men. In the reviews for 

 these two sciences (Schmidt's Jahrbucher and the Zoologischer Jahres- 

 bericht of the Zoological Station at Naples) it is not even mentioned. 

 It appears that not only did other biologists and medical men attach 

 no importance to Roser's speculations, but that the author himself 

 did not claim any great value for them. I draw this conclusion 

 from the fact that five years after his first pamphlet he published 

 a second on inflammation and healing 1 in which he does not apply 

 his theory of immunity to explain these two phenomena. This 

 new work is of an even more speculative character than was the 

 first, and instead of attempting to show any relation between the 

 anti-infective part played by the leucocytes and their migration 

 during inflammation, Roser insists on the fundamental independence 

 of this phenomenon of healing. For him the inflammation, accom- 

 panied by diapedesis, must not be looked upon as a healthy reaction 

 of the body, but as a manifestation of disease. The heat which is 

 observed under these conditions must be attributed in part at least 

 to the production of heat by infective micro-organisms. I must 

 confess that Roser's two pamphlets were unknown to me for many 

 years, and it was Hueppe who drew my attention to them by his 

 mention of them in the fourth edition of his work on bacterio- 

 logical methods 2 which appeared in 1889. I had then, independently 

 of the Marburg surgeon and by a totally different path, arrived at 

 my conclusions as to the part played by the amoeboid cells. At the 

 commencement of my researches on healing and immunity the 

 [540] passages cited above from the publications of Panum, Gaule, and 

 Grawitz were also unknown to me. Having long studied the problem 

 of the germinal layers in the animal series, I sought to gain some 

 idea of their origin and significance. The part played by the 



1 Roser, " Ueber Entziindung und Heilung," Leipzig, 1886. 



2 "Methoden der Bacterienforschung," 4 te Aufl., Wiesbaden, 1889, S. 10. 



