34 Notes on the Morphology of the Fucaccff. 



layers deep of small brick-shaped cells very rich in contents. In the 

 frond the same structure is repeated (plate x., figs. 3 and 4), but the central 

 thick strand has been flattened out and stretches across the frond, giving 

 it a leathery consistence. The cortex and epidermis are not so strongly 

 developed. 



The fruit-branches or receptacles are erect and torulose (plate X., 

 figs, i and 2) ; they occur along the axils formed by the frond and the 

 wing of the stem. They vary in size and are crowded together, some 

 rising directly from the leaf margin ; others are borne on a flat or 

 round pedicel, and branch irregularly. Each swelling of the receptacular 

 branch encloses a diclinous conceptacle. The male conceptacles as a 

 rule are at the base of the fruit-branch, the female nearer the top, 

 and both occur on the same branch. 



The antheridia in the male conceptacles are much branched, and are 

 accompanied by the usual branching paraphyses (plate X., figs. 5 and 6.) 

 The female conceptacles are crowded with oogonia. There is only one 

 oosphere cut off from the base of the oogonium (plate X., fig. 8), 

 and the pedicel cell, if present, is obscure. The paraphyses are large 

 with irregular cells rich in protoplasm and having a marked tendency 

 to branch (plate X., fig. 9). Harvey states that Seirococais occurs 

 only at Tasmania and on the south coast of Australia, and not further 

 west than Cape Northumberland. I find a record of it in the Herb. 

 Mus. Brit, as far north as Cape York in Torres Straits, well within 

 the tropics. 



The specimen I have examined was collected last year at Geelong, 

 by Mr. Bracebridge Wilson. 



A. LORRAIN SMITH. 



EXPLANATION OF PLATE X. 



Fig. i. Seirococais axillaris, part of plant. Natural size. 



Fig. 2. Part of frond with receptacular branch. Slightly enlarged. 



Fig. 3. Transverse section of frond ( x 150). 



Fig. 4. Longitudinal section of frond ( x 150). 



Fig. 5. Section through male conceptacle ( x 150). 



Fig. 6. Antheridial branch ( x 450). 



Fig. 7. Section through female conceptacle ( x 150). 



Fig. 8. Oogonium (225). 



Fig. 9. Paraphyses of female conceptacle ( x 225). 



