MERRILLOSPHAERA AFRICANA AT MANILA 



By Walter R. Shaw 



' the Department of Botany, College of Liberal Arts, University 



of the Philippines, Manila 



SEVEN PLATES 

 CONTENTS 



Four Gonidia. 



A form with sometimes six 

 Female Coenobia from Africa. gonidia. 



Typically Ovoid Coenobia at Ma- A form with sometimes eight 



nila. gonidia. 



Asexual coenobia. * A Small Form. 



Female and bisexual coenobia. Summary. 



Male coenobia. Revised Diagnosis of the Species. 



Literature Cited. 



INTRODUCTION 



In preparing accounts of the larger Volvocaceae found at 

 Manila I have left to the last a species that can be easily put 

 in its place beside its nearest relatives in the family. This 

 is the species that was described by West (10) from Albert 

 Nyanza, in Africa, under the name Volvox africanus and after- 

 wards reported from the Ussangu Desert, also in Africa, by 

 Rousselet ('14) who submitted material containing sexual coe- 

 nobia to West for description (West, '18). This species, with 

 others, was collected by Dr. M. A. Barber in the vicinity of 

 Manila in July, 1914, and by myself at various later times, and 

 is represented in my bottles, preparations, and micrographs by 

 examples in most of the varied stages of the life cycle of the 

 species, and with a diversity of form considerably greater than 

 was shown by the material described by West from Africa. 



Material associated with this species, and in most cases more 

 or less abundantly mixed with it in the ponds, bottles, and prep- 

 arations, led me to propose the separation from Volvox of those 

 species in which the somatic protoplasts are without proto- 

 plasmic connecting filaments. Some of those species have their 

 gonidia, the asexual reproductive cells, differentiated at an early 



