I' ' I 



:rs only ii ind varies in charactei according to the shape ol 



the lateral .ij.pt- It is from the approximated or contiguous ends of the lateral appen 



tli.it thi is formed. For instance, in U. indica fig. 53 and U. argentea 



ple monostromatic pseudo-parenchyma. In U. flabellum it is firmer and 



smaller elements. In U. pahnetta y U. spinulosa and U veriicillosa 



th, superficially from the two surfaces ol the frond, form a loose furry cor- 



rhe deposition of calcium carbonate either strengthens on the one hand 

 th< the component elements of the cortex or, on the other hand, helps to bind 



ose spinose lateral appendages into a more or less continuous mass. 

 1 ns. rhe filaments do nol normally coalesce in the upper margin <>t" the frond 

 i, in the manner characteristic of the central strand in the articulations of Halimeda. 

 int in U. ii/\ r c)i/id, at the base "l the marginal proliferations of the frond, we have occa- 

 mally noticed .1 distinct fusion of two filaments into one, which thereupon branches dicho- 

 tously in normal fashion. This however is apparently of rare occurrence and is always 

 difficult to detect, being obscurrd l>v the presence of numcrous lateral appendages. In other 

 two or more filaments are found coheriner tosrether laterallv, lmt not fusiner, at the base 

 of a proliferation. Whether perchance these junctions or cohesions may somehow be due to 

 fortuitous injury of the apices of the filaments al an earlier period, we are unable to say. Be 

 this as it may, we have in a few species commonly noticed that at the base of a prolifera- 

 tion, the outline of the previous margin of the frond is plainly indicated l>v a zone consisting 

 of a deformed thickening of the filaments (for a length of 20 — 30 u.) and of their walls. And 

 further, these thickened filaments end each in a blind apex, the new growth consisting ol a 

 single branch (not a dichotomy), which lias emerged a little below the aforesaid apex. This 

 shows clearly that there was for some reason a resting staj^e bcfore the forming ol the new 

 iliferation. We have noticed that snch a zone is sometimes marked in U. verticillosa by .1 

 thin fringe "f short loose excurrent branches of the frond-fïlaments. 



Stipes. The stipes, as shown above. is monosiphonous in the simplest species, U. 

 . and in small specimens of U. papillosa and U. glaucescens. In older plants 

 of these two latter species, the stipes becomes polysiphonous : in U. papillosa by the produc- 

 tion of rhizoids (fig. 37) which descend and form a covering of the original siphon ; and in 

 U. glaucescens by the production of branches (fig. 43) which become bound together and 

 eloped by a cortex composed of ramified lateral appendages, such as characterise the other 

 •cies of Udotea. The stipes-structure of U. orientalis is well figured under the name U. 

 %lutinata by Okamura (Icones of Japanese Algae I. [908 tab. XLV figs. 9, to). In the 

 i which have a corticated frond, the lateral appendages of the stipes-filaments usually 

 iw a broad resemblance to those of the frond-filaments The corticated stipes is simple in mosi 

 the species, but is very shortly branched at the apex in (J \ glaucescens and U. Wilsoni (fïg. 6< 

 Root-mass. The root-mass consists of a loose felt-work, which is composed ol .1 

 ratively small number of fairly straight, thick filaments, bearing throughout their length 

 icles of repeatedly and furcately branched, tapering, slender, colourless root- 

 These root-hairs become interlaced with each other and with the particles ol 



