322 



FINE-STRUCTURE OF PROTOPLASMIC DERIVATIVES 



III 



marketed in Japan under the name of "Konyaku". The technical com- 

 mercial product consists of irregularly bordered granules which light up 

 in a quite irregular manner between crossed nicols and reveal no ordered 

 structure (Fig. i6oa). But when these granules of konyak are observed in 

 water, they are seen to undergo a remarkable change. Under the very eyes 

 of the observer, they swell and assume a spherotexture, exhibiting a positive 



a) 



b) 



Fig. 1 60. Alannan granules of konyaku {Amorphophallns konjak) in the polarizing micro- 

 scope. Embedding medium a) xylene; h) water; there is the transient appearance of a 



spherite cross. 



spherite cross (Fig. i6ob). After a time the appearance becomes fainter 

 and eventually vanishes altogether, because the swelling is not limited, but 

 continues until solution takes place. 



This phenomenon may be interpreted as follows: The mannan chains, 

 which are comparable to the amylose chains, in the dry konyak granule 

 (which it is best to examine in a hydrophobic embedding medium, such 

 ac xylene or Canada balsam) are arranged in bundles that accumulate in 

 the granule without any defined orientation. This explains why the polar- 

 izing picture is irregular. As soon as water is added to these chains, 

 however, they are hydrated, become mutually mobile and align themselves 

 radially and this results in a spherotexture. The conditions are much the 

 same as those in myelin figures (see Fig. 47, p. 56), except that hydration 

 is not limited to one hydrophilic pole of the molecule, but encompasses 

 the entire mannan chain and ultimately spreads to such an extent that the 

 individvial thread molecules become independent of each other and go into 

 solution. 



