158 RESEARCHES ON FUNGI 



physes are so arranged that they form a mosaic-work pattern. A 

 close inspection of the drawings A and B in Fig. 61 (p. 156), whicli 

 were made with the camera lucida, enables ns to formnlate the 

 following rules for the distribution of the basidia : 



(1) A long basidium is nearer to one or more short basidia than 

 to any other long basidium. 



(2) A short basidium is nearer to one or more long basidia than 

 to any other short basidium. 



(3) The short basidia are always a little more numerous than the 

 long basidia. 



The first two rules might be combined in a single statement 

 running thus : like basidia tend fo repel one another more than unlike 

 basidia. Another way of putting this is : like basidia tend to repel 

 one another and unlike basidia to attract one another. 



In Fig. 61, B (p. 156), is shown the exact distribution of the 

 basidia on a particular area of the mature hymenium ; but the para- 

 physes have been omitted, and certain dotted lines have been added 

 arbitrarily in order to indicate what may be conceived of as lines of 

 organisation. One can perceive that, in general, there are two sets 

 of lines which tend to cross one another. If one traces one of these 

 lines across the field, one finds that long and short basidia alternate 

 along it in a fairly regular manner. Occasionally a line bifurcates 

 so that we get two short basidia where, for a regular pattern, only 

 one would have been necessary. In the whole area, as a matter of 

 fact, the long basidia are to the short basidia in the proportion of 

 100 to 125. It is conceivable, although I have no evidence to offer 

 in support of the idea, that, after the general pattern or arrangement 

 of the elements in the hymenium has been established in the first 

 instance, the paraphyses are subsequently stimulated so that they 

 tend to swell in a greater degree between two like basidia than 

 between two unlike. By this means, adjustments of the pattern cf 

 the hymenium might be effected in such a way as to secure the dis- 

 tribution of the basidia according to the rules already formulated ; 

 and thus would be secured the requisite safety for the development 

 and discharge of the spcres of every single basidivim. The forces 

 at work in bringing si ch a finely-wrought mosaic-work as the 

 hymenivmi of a Coprinus into existence, must surely be complex. 



