502 ('. Cl-IFFOKD DOBELL. 



Figs. 4ti-41>. — Four successive stages in tlie division o£ a Micro- 

 coccus similar to those seen in the preceding figure. Note the 

 characteristic dumh-bell figure assumed by the nucleus during division. 

 (Compare with figs. 24-29. Plate !(>.) 



Fig. ")(.». — Three coccobacillar forms. The nucleus is in the form of 

 a filament, bent in a more or less spiral or zig-zag manner. 



Fig. 51. — Grouj) of short Bacilli, with nuclei of characteristic spiro- 

 gyr;i form. 



Fig. 52. — Chain of Cocci in which division is taking place. Note the 

 zig-zag or spiral form assumed by some of the dumb-bell figures of the 

 dividing nuclei. (This figure is drawn on a very slightly larger scale 

 than the others.) 



Fig. 53. — Small Bacillus with nucleus in tlie form of a short rod. 



Fig. 54. — Similar organism to the preceding, in the act of dividing 

 into two. The nuclear rod is completely divided into two parts. 



Figs. 55-60. — Large Bacilli of spirogyra type. 



Figs. 55-57. — Three individuals, showing three different arrangements 

 of the nuclear filament. 



Fig. 58. — Spore-bearing individual of same species. (A single ter- 

 minal spore is formed — as in B. spirogyra.) 



Fig. 59. — Dividing individual. The two halves of the nuclear fila- 

 ment are still joined hy a vei-y slendei' chromatin thread. 



Fig. 60. — Another dividing individual. The nucleus — which is very 

 mnch contorted (cf. fig. 59) — has already sej^arated into two parts. 



Fig. 61. — Three short Bacilli, with nuclei of spirogyra type, from 

 large intestine of Bufo uielanostictus. (1 jjer cent, osmic acid, drop 

 method ; Giemsa's stain.) 



Fig. 62. — Long, curved Bacillus, with ii'regidar varicose nuclear 

 filament. Large intestine <if Bufo melanostictus. (1 per cent, 

 osmic acid, drop method ; Giemsa's stain.) 



Fig. 63. — Group of Bacilli froui large intestine of Lacerta muralis. 

 The nucleus is in the form of an irregular knotted rodlet. The 

 lowest organism is undergoing division— the nucleus being already 

 divided into two. (1 per cent, osuiic acid, drop method; Giemsa's 

 stain.) 



Figs. 64, 65. — Slender Bacilli f)-om large intestine of Lacerta 

 muralis. Nucleus in the form of cln-omidia. (1 jier cent, osmic acid, 

 drop method ; Giemsa's stain.) 



Figs. 66, 67. — " Fusiform Bacteria ■' froui large intestine of Triton 

 vulgaris. The upper individual of the pair shown in fig. 66 is 

 dividing. Note the nuclei — in tlie form of double granules. Fiu:. 67 is 



