478 



Mr. E. C. Hort. 



8. At first sight inspection of the drawings in figs. 1 and 2, and of the 

 photographs of killed organisms, suggests meaningless chaos. 



9. Once, however, it is grasped that reproduction by gemmation is the key 

 to the " aberrant " forms shown, and that gemmation may be terminal, median 

 or superficial, the main types fall into line. 



That true gemmation occurs of these three types is shown in Plate 20, 

 representing growth from single organisms on the warm stage. 



10. There is no evidence that a given strain represents a mixture of several 

 strains, this suggestion being largely excluded by study of gemmating forms 

 before fission has taken pfece, and by study of the actual process of gemmation 

 on the warm stage. 



11. The correct explanation of the superficial gemmation origin of the 

 crucial and radiate forms shown is more difficult to establish than is that of 

 the terminal, median and simple superficial forms of gemmation. 



The points against a mere apposition explanation of these crucial and radiate 

 forms are as follows : — 



(a) Strict rectangular symmetry is the rule. 



(b) The diameter of the central, brightly refringent node is frequently 



twice that of the organism which might otherwise be interpreted as 

 lying in contiguity. 



(c) Superficial buds can frequently be observed on the parent bacillary 



stem before " sprouting " has commenced, and during the act of 

 sprouting. 



12. Sagittal segmentation of buds can frequently be seen, both in the case 

 of dried organisms and of single living organisms, before separation from the 

 parent stem has begun. This sagittal segmentation can be seen in the 

 terminal, median, and superficial buds. 



13. Transverse segmentation of buds — ordinary binary fission — also 

 frequently occurs, the parent stem also presenting buds undergoing sagittal 

 segmentation, the actual occurrence of which was watched on the warm 

 stage, as shown in Plate 20. 



14. Undetached buds may vary in size from about 0*1 yu. to several fi in 

 their greater diameter, every intermediate size — from the filterable to the 

 non-filterable — being capable of recognition in the same film in favourable 

 cases (vide photographs of dried films). 



15. The appearance of minute buds on a large scale is inconstant in broth 

 cultures, as observed in dried films. In the study of growth from single 

 organisms on the warm stage it occurs frequently, only a relatively small 



