CHAPTER VI. 



TIM <;l-:i; MI NATION OF THE ENDOSPORE. 



56.-First Type. 



WIIKN the >|ioiv is exposed to favourable conditions as regards nutrition, it 

 abandons its dormant state and begins to germinate by commencing to absorb 

 liquid from the surrounding medium. It then becomes distended, its high 

 refractive power gradually diminishing in the same proportion. Further 

 development can then proceed in three ways. 



The first type of spore germination was accurately observed by H. BUCHNKI; 

 (111.) in /Ifici/fttx ((ntkracis, the producer of anthrax, and afterwards discovered 



KM;. 21. KM;. 22. Clogtridiuui but\ rinnn. 



Bacillus antbracis. Spore formation. 



<-. rniin.-iiioii of sporee. ( , rjp( , ,.,, 



I. the ripe spore before l>. ditto expanding in nutrient solul ion. 



uermination begins; i, <. final di ineiisions attained, and separation o!' 



2, 3. three Mirre-sive exosporimn from endosporiutn visible. 

 stages of ^eriitination ; <7, /. voting rod esc:ipin^ 'from polar extremity 



3. the fully develojRjd of spore capsule-. 



rod. ((I'll i" !>' 1'iii-y.) ( .(/'fir I'rir.uioii-xki. ) Ma.u'ii. IO2O. 



M.-IUII. about 600-700. 



in other kinds; as, for instance, by PRA/MOWSKF (II.) in a fission fungus named 

 by him " mistbakterie " (dung bacterium), and in a second species isolated from 

 fermenting urine. The progress of germination in this type is very simple 

 (Kig. 21). The spore, gradually acquiring the normal dimensions and functions 

 if the vegetative form, soon divides and reproduces by fission. According to 

 several observations made by Brefeld, the external layer of the spore-membrane 

 (" exosporium ") separates during this germination process and swells up. This 

 harmonise^ well with the remark made in a previous paragraph, that the spcuv- 

 c.i|ule probably consists of two layers, distinguished as exosporium and endo- 

 sporiuin. 



57. Second Type of Spore Germination. 



BKieroaeopieally the initial stage of the process is identical with that described 

 in the foregOUg paragraph ; the refraction of the spore diminishes and an in- 

 crea>e in .-i/.e occurs. Then, however, the contents of the spore are elaborated 

 into a new rod, which is surrounded by a thin membrane, and which, by its 



further growth. l>ur>ts the spore c.-ipsule. 



Thi> rupture is eflected at the point of least resistance, the position of which 

 and omx-qwutly the mode of escape of the germ varies in different species. 



In f'/i*f rii/ i tun Imt ijricinn, ('!. I'oh/ni i/.rit, and a few others, the spore capsule 

 opens at one of the poles, so that the direction taken by the young rod in its 



!>u is in a line with its length, as shown in Fig. 22, d. The expulsion is 



