254 RESEARCHES ON FUNGI 



of the hymenium : they protect the young asci when they are 

 developing and pushing upwards, and they support the mature asci 

 mechanically, preventing them from having their apices forced 

 down\\ards when they are firing their jet of spores and sap upwards. 

 If the paraphyses were reduced to such a minimum that the asci 

 were in lateral contact with one another, many of the asci would 

 not be able to discharge their spores properly. To make this clear, 

 let us imagine that on the right-hand side of Fig. 120, A, the five 

 asci most in view were in contact one below the other. Then to 

 secure the aerial dispersion of all the spores it would be necessary 

 for the five asci to be discharged in succession from above down- 

 wards and in no other order ; for, if of any two adjacent asci in the 

 row of five the lower one discharged before the upper one, since the 

 opening of the exploding ascus looks upwards and since an exploding 

 ascus contracts in length, most of the eight spores of the lower ascus 

 would be shot against the lower side of the upper ascus and so would 

 not escape from the mouth of the apothecium. From these con- 

 siderations it is seen that it is best in Sarcoscyi^lia protracta for the 

 asci to be well separated from one another, especially in the vertical 

 direction. If one regards the right-hand side of Fig. 120, A, one 

 can see that, if one of the middle asci explodes, as it contracts in 

 length and ceases to be protuberant all the spores can be shot away 

 without any of them hitting the lower side of the ascus which is 

 above it. Evidently, the number of the paraphyses is correlated 

 with the spatial arrangement of the asci necessary to secure that all 

 the spores from each ascus shall be efficiently discharged through 

 the cavity of the apothecium into the outer air. A reduction in 

 the number of paraphyses in the hymenium would therefore be 

 disadvantageous . 



Summing up, we may say that correlated with the conical form 

 of the cavity of the apothecium in Sarcoscypha protracta, and making 

 for efficiency in the production and Uberation of spores by the 

 hymenium, are the following arrangements : (1) the obHque upward- 

 looking openings of the asci formed at the moment of spore-dis- 

 charge ; (2) the obUquely upward inchnation of the spores in each 

 ascus ; and (3) the relatively distant separation of adjacent asci 

 by paraphyses, particularly in respect to vertical planes. 



