THE METHOD OF CLEAVAGE IN THE 

 SPORANGIA OF CERTAIN FUNGI 



Carl A. Schwarze 

 [With Plates 15 and 16 and Text-figures A-F] 



The division of the multinucleated sporangia into spores and the 

 delimitation of the sporangium from the sporangiophore by a 

 dome-shaped cross partition present many features of special cyto- 

 logical interest. Erroneous views on both processes are still cur- 

 rent in the literature and as to the formation of the columella cer- 

 tain textbooks, both old and recent, are still entirely out of 

 harmony with the facts. The literature dealing with the common 

 molds, Mucor and Rhizopus, constitutes some of the earliest con- 

 tributions to mycological research. 



Corda (11), the " father of microscopic mycology,'' gave us the 

 first description and illustration of the method of the columella and 

 spore formation in Ascophora mucedo, now known as Rhizopus 

 nigricans. He writes : " Nun rundet sich die kolbige Verdickung 

 allmalig, und gleichzeitig erfiillt die gelbe Masse ihren Hohlenraum 

 vollig . . . aus dem unteren Theile mit dem Stiele verbunden 

 beginnt allmalig die polsterartige Erhebung der Columella, und 

 gleichzeitig beginnt die obere Masse undeutliche und noch isolirte 

 Zellen zu bilden welche sich vermehren und endlich in enger Ver- 

 bindung die ganze Sporangie erfullen." His figure 78 (5-9) de- 

 picts the columella as at first slightly arched and gradually pushing 

 up into the sporangium, while the spores are represented, at their 

 very inception, as polyhedral masses. These figures of Corda are 

 doubtless responsible for the persistent, erroneous accounts of the 

 columella formation still to be found in certain textbooks, though 

 Corda's statements were soon contradicted by Fresenius. 



Fresenius (20), also studying Rhizopus nigricans, states he was 

 unable to observe the phenomena described and figured by Corda. 

 He writes : " Was iiber Bau und Entwickelung der Sporen bei 

 Corda gesagt und abgebildet ist scheint mir vollig aus der Luft 

 gegriffen zu sein." Further, also as early as 1872, Brefeld (7), 



143 



