O 



94 C. F. ROUSSELET ON TWO SPECIES OF AFRICAN VOLVOX. 



Cathypnidae, and we considered it very desirable to obtain, 

 if possible, specimens of the new species described. So after I 

 had ascertained that the author was working at the Zoological 

 Institute at Lemberg University I wrote to Dr. Jakubski 

 asking him to be good enough to send me a little of the material 

 containing the species of Rotifera. Some time in the spring of 

 1913 the Doctor very kindly sent a few slides and also about eigh- 

 teen tubes of Plancton material collected in German East Africa. 

 By this time Mr. James Murray had left England on his way to 

 the disastrous North Canadian Arctic Expedition, from which 

 he has not returned, and being myself much occupied with other 

 work, 1 delayed the examination of this material until the spring 

 of the present year, when I received a polite reminder from the 

 sender asking for the return of his tubes as soon as convenient. 

 This request obliged me to look over the contents of the tubes 

 without further delay, which was clone in May and June last. 



In his paper the author states that in deserts of German 

 East Africa pools and ponds are rare and can only be found after 

 heavy rainfalls, and are then shallow and last a very few weeks 

 only, but often develop a considerable amount of Plancton 



organisms. 



In two of the tubes, amongst various Rotifera, I was surprised 

 and fortunate to come across numerous colonies of Vol vox 

 which I at once recognised as the same two species from 

 Africa described by Prof. West four years previously. Moreover 

 both species were present in various sexual stages with 

 androgonidia and oospores, the male and female colonies, as 

 well as the vegetative colonies.* The ripe star-shaped oospores 

 of the large Volvox Rousseleti in particular are very fine and 

 remarkable, and these specimens will now enable Prof. West 

 to describe the complete life- history of both these African species, 

 which appear to be widely distributed in that continent, though 

 not as yet known from any other part of the world. 



After completing my examination of the material I returned 

 all the tubes to Dr. Jakubski at Lemberg in Galicia early in 

 July, but have not heard whether they reached him. The 

 tragedy of the situation is that at the end of the same month 

 war was declared and Lemberg (Lwow) was one of the first 

 towns of importance taken and occupied by the Russian army, 

 and it is at present impossible to ascertain what has become of 

 either my correspondent or his collection of specimens. 



You will agree that it was a piece of extraordinary and 

 remarkable good luck that these collections came into my hands 

 and at this particular time. 



* Slides were exhibited by Mr. Eousselet showing the various sexual 

 stages. 



Joum. Quekctt Microscopical Club, Her. 2, Vol. XII. , No. 75, November 1914. 



