MU COR ALES 249 



cutinized, somewhat incrusted with crystals of calcium oxalate, 

 soon disintegrating; sporangiospores smooth, yellowish, ellip- 

 soidal; zygospores formed on the mycelium; copulating branches 

 shaped like tongs and forming the zygospore between their tips; 

 suspensors provided with dichotomously branched, dark brown, 

 rigid outgrowths, which radiate in various directions and have 

 the aspect of antlers (Fig. 86), not enclosing the zygospore as in 

 Ahsidia. 



Fig. 8G. — Phycomyces riitens (Agardh) Kunze. (a) Early stage in conjugation 

 showing outgrowths arising from one of the suspensors. (6) Same somewhat 

 later, (c) Mature zygospore; the outgrowths from the suspensors rigid and 

 dichotomously branched, (o, after Blakeslee, 1904; b, after Keene 1919; c, 

 after van Tieghem and le Monnicr 1873.) 



The best known species is P. nitens (Agardh) Kunze & 

 Schmidt. At least five other species have been recognized: P. 

 splendens Fries, P. microsporus van Tieghem, P. pirottianus 

 Morini, P. spinulosus Morini, and P. hlakesleeanus Burgeff . 



9. Zygorhynchus Vuillemin (1903 a: 116). 



Sporangial stage as in Mucor; zygospore formed in a charac- 

 teristic manner from wholly dissimilar gametangia (Fig. 87); 

 all species homothallic; genus merged with Mucor by Lendner 

 (1908 6:72). 



The genus contains relatively few species: Z. heterogamus 

 Vuillemin (1903 a: 117); Z. moelleri Vuillemin (1903 a: 117), 

 Z. vuilleminii Namyslowski (1910 h: 152), Z. dangeardi Moreau 

 (1912 a: 67), Z. hernaldi Moreau (1913 c\ 256), Z. japonicus 

 Kominami (1914: 3). 



The details of zygospore formation are discussed by Gruber 

 (1912: 126), Atkinson (1912: 151), and Blakeslee (1913: 241). 

 The terminal portion of an erect hypha is delimited by a septum 

 from the part below. A lateral branch then pushes out just 

 beneath the septum, grows upward, and recurves to meet the side 



