138 THE ROYAL SOCIETY OF CANADA 



in regarding them as resistant forms ? Are they developed not so 

 much in order to withstand adverse conditions as to be a means of 

 abundant multiplication capable of easy transport and diffusion ? 

 It is now my pleasant duty here to thank Prof. Lloyd and Prof. 

 Derick of the Botanical Department, for their interest and assistance, 

 and to acknowledge in all gratitude that in whatever measure this 

 paper possesses of scientific value it owes to Prof. Adami, under whose 

 supervision, as head of the Bacterial Department of the University, 

 this work has been carried out. 



APPENDIX. 



When the above paper was presented at the Montreal Meeting 

 of The Royal Society in May, 1914, the results were regarded as so 

 opposed to the popularly accepted views regarding the heat resistance 

 of spores as to warrant some criticism. Principal Harrison of Mac- 

 donald College has been so good as to tabulate what he regards as 

 debatable points. They are as follow: 



I. Species nomenclature. 



II. Whether laboratory stock cultures have the resisting power 

 of freshly isolated organisms. 



III. Whether there does not exist a discrepancy between these 



results and those recorded by other investigators and 

 in the text books. 



IV. Whether if these results hold good, the sterilisation of 



media should not be easier than as a matter of practical 

 experience we find it to be. 



If I may be permitted to discuss these criticisms in order, I 

 would say: 



I. As regards nomenclature, I freely acknowledge that the cir- 

 cumstances under which the work was conducted, forbade my making 

 a precise analysis of the cultural characteristics of the different spore- 

 bearing growths at my disposal. The problem I set out to solve 

 was to determine whether bacterial spores as a body possessed a com- 

 mon maximum heat resistance. What seemed necessary, therefore, 

 was to select a collection of different types of bacterial growth and test 

 their heat resistance. The exact nomenclature of these types was for 

 this purpose a secondary matter, and while to round off my investiga- 

 tion I should have wished to name my cultures with precision, the time 



