iQoS] BRIEFER ARTICLES 



195 



of the antheridial branches 

 raise the Chapel Hill form to 



exseptate ori 

 importance 



species 



the same group with A. racemosa and its variety stelligera, in which they 

 are absent, must modify to some extent our ideas of the distinctive value 

 of this character. Maurizio sufferests that sub-ooeronial antheridia with 



P<^gv 



He savs;^ 



hypog}- 



erhohen, wodurch die ofifenbar eine naturliche Gruppe bildenden hypog>Tien 

 Fomien von der Gattung Saprolegnia abgetrennt vviirden. Charakterisirt eine 

 Querwand in der Traghyphe den in das Oogonium eindrin^enden Fortsatz als 

 emen Befruchtungsschlauch wie dies bei den zwei vorli 



* 



1st ... . 1st dieser ein Analogon des Befruchtungsschlauches bei Pythium jerax 

 de Bar}', so miisste man auch die letztere Species von den Pythiumarten trennen. 



be considered 



forms 



A. raceniosa stdligera^ and A. hypogyna. These three forms, which \^ 

 might call the Racemosa group, are distinctly segregated as Maurizio 

 Hypogyna group among the species of Saprolegnia,^ 



In the cultivation of Achlya hypogyna it was found best to use sma 



gnats 



culture could then be made in han 

 and the growth studied without mis 



A marked peculiarity was the scarcity of zoosporangia. These were 

 found only in young cultures, appearing about 24 hours after infection; 

 two are shown in fig. i. The oogonia, however, were very abundant; 

 their usual arrangement is shown in fig.^ 2. A mature oogonium and 

 antheridium of typical appearance are represented in fig. j. The fertiliz- 

 ing tube in this case is branched near its base. In a verj' few cases the 

 oogonia are oblong (fig^ 4), and some intercalary ones are occasionally 

 ^^^ O^^- 5)- ^When^the stalk is very short, the antheridium may extv..d 

 some distance into the main hypha (fig. 6). It v. Ill be noted that one of 

 the oogonia here shown has no projections on its wails; this peculiarity 

 ^ of ver}^ rare occurrence. In one case a hanging drop containing a gnat 

 was infected with a sporangium in which the spores were formed but not 

 yet discharged, Tne spores remained in the sporangium, but sent out 



^ Beitrage zur Biologic der Saprolegnieea. Mitteilxmgen des Deutschen Thch&tm- 



erem 



Jahrb. Wiss. Bot. 29:75-131. ^■ 



- x'lura 79:109-155. pis. J~J. 1594. 



896. Beitrage zur Bioiogie der Saprolegnieen. Mitteii. Deutsck Fiscberei-Vemns 



^^ : i-^. figs. 19, 1809. 



