Takeda. — Dysmorphococcus variabilis , gen. et sp. nov. 155 
iodine. The nucleus, which is very small, is situated at the bottom of the 
central protoplasmic mass within the hollow of the chloroplast. So far no 
contractile vacuoles have been observed. 
As already mentioned, the protoplast varies in size, being as a rule 
much smaller than the shell, but sometimes almost filling up the lumen of 
the latter. The smallest protoplast observed measures 8 /x in length and 6 /x 
in transverse diameter, while the largest one reaches 12 ft in length and 
10/xin transverse diameter. The variation in size of the protoplast does 
not run parallel with the size of the shell ; thus a small shell may be found 
to possess a protoplast of relatively large size, while a large shell may con- 
tain a small protoplast. The variations in the size of the protoplast are 
probably connected with its growth, the proportional size of the protoplast 
being presumably an index of the age of the specimen. 
It is much to be regretted that we have no knowledge regarding the 
reproduction of this Alga. 1 It may, however, be presumed that the proto- 
plast, when it has reached a certain size, divides into possibly two or four, 
and gives rise to daughter-cells within the original shell. Hence the 
examples with a relatively large protoplast may perhaps be regarded as 
a stage preceding asexual reproduction. At a certain stage after division 
of the protoplast into daughter-cells, the shell no doubt breaks and liberates 
the young naked individuals, each of which sooner or later must secrete 
a shell for itself. It seems improbable that the daughter individuals become 
provided with shells within the mother-shell. 
Since the life-history of this Alga is not known, nothing precise can be 
stated as to the affinity of this peculiar organism. However, so far as the 
vegetative characters are concerned, Dysmorphococcus undoubtedly possesses 
all the essential features of the Volvocaceae. Amongst the described mem- 
bers of this family, the organism under consideration appears to be closely 
related to Coccomonas , 2 which, however, differs in having a definite cell- wall 
and a large single aperture in the shell for the emergence of both of the 
flagella. For the present it may be convenient to place our new genus in 
the Fhacoteae, a sub-family of the Volvocaceae. Since this new alga 
possesses two cilial apertures in the shell, it may be suggested that the 
organism should be compared with Isococcus , 3 which has been described as 
having an envelope of a similar nature. An examination of the original 
preparations of Isococcus has convinced me that there is no relationship 
1 No stage of division has been found either in nature or in the laboratory cultures, the latter 
having been not very successful. As the author is returning to Japan shortly, it is impossible for 
him to continue his investigations. Further study of this singular organism, in particular with 
regard to reproduction, is therefore left to the hands of those botanists who are in a position to obtain 
fresh material. The pond in which the organism was found lies near the south-eastern corner of 
Conduit Wood and can easily be reached by entering the Park through Richmond Gate. 
2 Cf. Wille, in Engler and Prantl, Pflanzenfam., i. 2, p. 40, Fig. 22, M, n (1897), and also his 
Nachtrage to Chlorophyceae (1909). 
3 Fritsch, in New Phytologist, vol. xiii, p. 341 (1914). 
