148 THE JOURNAL OF BOTANY 
ascertain some details which are incapable of being studied in 
herbarium material. Briefly stated the results are a description 
of the true mode of formation of the reticulum and of the deve- 
lopment of the tetraspores, the spermatangia, and the cystocarp. 
(1) The frond is more or less flabellate in shape, and from an earl 
typ 
growth exhibited respectively by the species M. fragilis, M. pa- 
vonia, and M. flabelliformis, (2) The tetrasporangia are borne on 
the gonimoblast-threads arise from the central-cell and are usually 
all uninucleate. They produce the carpospores, which are also 
ucleate 
We are greatly indebted to Herr Svedelius for this careful 
piece of work. It is one which appeals rather to the morpholo- 
Floridee which is characterized not onl by its intercalary 
growth, but by its multinucleate cells. The plates and figures 
which illustrate the text are excellent, and the exposition of the 
subject is clearly rendered. ASE S Gere 
A Monograph of the British Desmidiacee. By W. and G. 8. 
West. Vol. iii. Pp. xv. and 274, Plates 65-95. London: 
Ray Society. 1908. 
Tue third volume of Messrs. W. and G. 8. West’s monograph 
of British Desmids contains the description of one hundred and 
8 um 
