BLAKESLEE. — SEXUAL REPRODUCTION IN THE MUCORINEAE. 245 



Dispira Americana Thaxter. 

 Professor Thaxter informs me that the zygospore-like bodies found by 

 him iu couuectiou with his cultures of Dispira ('95) were probably acci- 

 dentally associated with it, and that they are doubtless referable to the 

 genus Parasitella recently published by Baiuier ('03). 



Massartia Javanica Wildeman. 

 This fungus was found by Wildeman ('97) in the mucus about terres- 

 tial algae which had been collected in Java from the bark of a tree aud 

 sent him as preserved material. Certain globose double stalked cells are 

 classed as zygospores, and stages of development are mentioned and 

 li^ures are given, but no other form of reproduction was discovered. 

 These cells, if zygospores, are more suggestive of Piptocephalis or Syn- 

 cephalis than of any other known forms among the Mucorineae, but the 

 foundation of a new genus on such imperfect data seems undesirable. 

 Although in Saccardo's Sylloge (vol. xiv, p. 437) this is put under 

 the Chytridiaceae, it can best be left among doubtful genera, where 

 "Wildeman himself places it. The hyphae connected with the cells in 

 question are separate, as far as shown. 



PART II. 



In Part I the investigations and theories of previous authors on the 

 subject of the present paper have been summarized, and the results of 

 the writer's own researches have been briefly outlined. It now remains 

 to present in Part II the body of detailed experiments which form the 

 basis of the conclusions already mentioned. It will be convenient to 

 treat the individual forms examined under the thallic groups to which 

 they belong, to which will be added a consideration of the phenomena of 

 hybridization. 



HETEROTHALLIC FORMS. 



The Mucorineae, as has already been stated in the Introduction, may be 

 divided into two main groups. In the horaothallic forms the mycelia 

 are bisexual and the zygospores produced are consequently formed 

 through the interaction of branches of the same mycelium. In the 

 heterothallic group, however, to be considered in this section, the 

 mycelia are unisexual and the zygospores produced are formed there- 

 fore through the interaction of branches of two mycelia which are 



