BV R. GREIG-SIIITH. 

 Table xi. — Sources of Nitrogen. 



69 



Phase Al is omitted from the table as all the tests were negative with the 

 exception of peptone plus glycerine which became ropy on the 13th and was stiU. 

 ropy on the 24th day. On tlie 19th day a smear showed that the liquid contained 

 95 % of A2 and 5 % of Al. 



On the 11th (B2) and 13th (A2) days the fluids were smeared on plates of 

 nutrient agar and counts were made of the approximate proportions of the phase?. 



Table xi(7. — Percentage Proportion of Phases. 



It is dilHcult to see any relation between the rojiiuess as determined ou Table 

 xio. -with the proportion of the phases. Even when the transition phases of 

 Al=Al(tr.) and of Bl^Bl(tr.) are included with the cohesive phases, there ap- 

 pears to be no reason for connecting ropiness with a particular phase of the 

 organisms. One is, therefore, inclined to the idea that in most cases the ropy sub- 

 stance is formed first and the alteration of phase occurs subsequentl3^ (compare 

 p. 64 1 . The altered phase may in some cases digest the preformed ropy substance. 

 The untabulated tests with phase Al showed that the nature of the infecting phase 

 largely determines the formation of ropiness. 



