30 Vol. XLTII., Art. 1 — E. Yendo : 



firms the observations made by Bowee, Valiante, Oltmanns, etc., 

 though tliere are certain points at variance with them. The mode 

 of formation of the " cryptostomata " of Alaria has been fully 

 elucidated by Mueeay.^) The present Y/riter^) observed parallel 

 cases in those of Costaria and Undaria. We are now on safe 

 ground when we say that the tufts of hairs found in fronds of 

 Laminariaceœ are different from the cryptostomata of Fucacese, 

 genetically and morphologically. Mueeay has already recognized 

 the diflerence as he expresses hesitation in applying the term 

 cryptostomata to the tufts of hairs of Alaria. 



Mueeay points out in the above quoted lines a morphological 

 gradation of the cryptostomata of Encœliaceœ, Cutleriaceao and 

 Dictyotaceœ. His idea appears to me by far suggestive when we 

 take into consideration all other brown algae wdiich bear the hairs, 

 and the development of such plants. I shall take this opportunity 

 to elucidate briefly the embryonal stages of Homœoslroma lati- 

 folium .T. Ag. 



The primary stage of development of Homaostrowa latifolium 

 J. Ag, is a discoidal monostromatic patch of parenchymatous cells 

 (Plate XIX, fig. 5). Some of the marginal cells elongate prostrate- 

 ly to form the rhizoidal filaments. ]SIeanwhiIe, the patch becomes 

 polystromatic. Some of the surface cells elongate upright, and 

 form confervoid bodies by successive transverse divisions. When 

 there are about 20 cells in a confervoid body the basal cells grow 

 longer than diameter and the middle and upper ones more or less 

 compressed and broader than height. Then a longitudinal division 

 through the median line takes place in the compressed cells. 

 Further multiplications of cells follow next to form a lii eir, mono- 



1) Mueeay : 1. c. 



2) Yendo : Development of C'ostarla, etc. 



