53 



In none of the cultures with AlCNGg)^ did the add- 

 ition of either Mg(N03)2 or Ca(NC2)2 bring about any alter- 

 ation at all in the behavior of the spores. Although many 

 other proportions of these pairs of salts might have been 

 tried, it appears probable that, if either the calcium or 

 magnesium salt, at any concentration, exerts any influence 

 upon the toxicity of Al{NC3)2, in any concentration, some 

 evidence in this direction would have been obtained from 

 the experiments which were carried out. This seems still 

 more probable from the fact that differerjt concentrations 

 of the alumintim salt alone produced markedly different eff- 

 ects upon the activities of the spores, a matter which will 

 now receive attention. 



In the highest concentration of Al(M03)3 used, 

 O.C045m, only a few local swellings of the spores were ob- 

 served. A blackening of half of the spore was frequently 

 found here, samples of spores so modified by the aluminum 

 salt being shown in Fig. 6 . No normal germination occur- 

 red in this solution. In the two lowest concentrations of 

 AlCNCg)^, however, much of the germination was normal. Al- 

 uminiom nitrate appears to influence the form of germination 

 occurring in these spores with much the same results as 

 have been described for cultures poisoned with Pb(NO,)^. 



The types of renewed activity which occur with Al(KO„) are: 



^ 3 



(1) the formation of a dark body occupying about half of the 

 spore, (2) the growth of a small local swelling at one end 



