140 



MORPHOLOGY AND LIFE-HISTOEY OF YEASTS. 



here it is the rule ; there it took place between the spores them- 

 selves, here only in the germ tubes proceeding from the spores. 

 This fusion is not of invariable occurrence, but is occasionally 

 hindered by the tubes (7'") taking different directions from the 

 start, or by the premature withering of one or the other of 

 them; or sometimes only one is formed, the adjacent cells 

 being prevented from germinating by circumstances, e.ij. age. 



Apart from SarcJi. Lud 



V°v) 



o 



Via. 147.— Sacch. anomalus Hansen, 

 germination. 



Spore 



ioif/ii, this method of 

 spore germination is 

 only known to occur in 

 one other species of 

 Saccharomyces, which 

 was discovered by J. 

 Behrens (VIII.) on 

 fresh hop cones. 



The thu-d method of 

 germination is found in 

 the group Sarch. ano- 

 mahis, and differs from 

 the first type solely in 

 the influence exercised 

 by the peculiar shape 

 of the spores. Three 

 examples are illustrated 

 in Fig. 147. These 

 relate to sowings of 

 spores taken from old 

 gypsum-block cultures 

 and grown in beer wort 

 intheRanvier chamber, 

 the top row being kept 

 at 28° 0. and the other 

 two at 23° C. The gei-minating spore swells up, and gradually 

 puts forth a number of buds at various points of its surface, 

 these in turn reproducing by budding. During this operation 

 the hat-brim-like projection round the spores disappeared in 

 the middle series (6), but remained in the other two (a and c). 



A fourth type of spore germination is exhibited by Sarrh. 

 guftulafux. This fungus is an invariable inhabitant of the 

 contents of the stomach and intestines. It also occurs in the 

 excrement of the full-grown rabbit, and was first discovered 

 therein by R. Remack in 1845. It was classed along with the 

 yeasts by Robin in 1847, under the name Crijjtfocorrus (jutfulafus, 

 and finally recognised as a Sarch aromyce.^ by Buscalioni, in 1896, 

 as the result of a searching investigation. In this species, 

 which does not bud until about 37° C, but is capable of sporu- 

 lation at about 14" C, and thus forms in this respect an 



a. A spore at the coniniencenient of germination, 

 witli the brim turned towards the left; a' is the same 

 after seven hours, one bud having been formed ; a" is 

 the same after twelve hours, a second bud appearing 

 on the spore ; a'" is after fifteen hours ; and a"" after 

 twenty hours. 



h. A spore with tbe )irim turned towards the right ; 

 b' the same after ten hours ; b" after twenty-one hours ; 

 h"' at the end of twenty-four hours ; b "' after twenty- 

 five hours ; h'"" after twenty-seven hours, the spore 

 with its daughter-cells having turned through an angle 

 of 180' in the nutrient solution. 



<;. Is a spore with the brim turned downwards ; c' the 

 same after eight hours ; c" after ten hours ; c'" after 

 twenty-four hours. 



Magn. 1000. (After Hantten.) 



