On the Development of the Cystocarp 
in Rhodomelaceae (II). 
BY 
REGINALD W. PHILLIPS, M.A., B.Sc., 
Professor of Botany in the University College of A T orth Wales, Bangor. 
— ~M 
With Plates XII and XIII. 
I N an earlier number of the Annals of Botany (1), I gave 
an account of some observations on the development 
of the cystocarp in certain Rhodomelaceae of the genera 
Rhodomela and Polysiphonia . The results of these investi- 
gations showed that in the four species then under considera- 
tion there was a remarkable uniformity in the intimate 
structure of the procarp at the moment of the fertilization of 
the trichogyne ; but that when spore-formation had set in, 
there was a varying degree of retrogressive absorption by the 
sporogenous cell of the cells from which it had been derived. 
The real nature of the sporogenous cell — whether it con- 
stituted in itself the auxiliary cell, as Schmitz averred, or 
was derived from the auxiliary (pericentral) cell — was left 
undetermined pending the direct observation of the conju- 
gation of the carpogonium with an auxiliary cell. 
The genera Rhodomela and Polysiphonia represent, however, 
only two of several groups of genera into which the family of 
the Rhodomelaceae has been subdivided. Agardh (2) divides 
[Annals of Botany, Vol. X. No. XXXVIII. June, 1896.] 
