746 SUMMARY OF CURRENT RESEARCHES RELATING TO 



than two. Where there are two, the one grows out as the axis, while 

 the other may be regarded as a branch. Further development is very 

 varied, but one character seems to be fairly constant. On one or other 

 of the rhizoid-branches there arises a short and thick cell, from which 

 grows a bushy short-celled group of branches, the cells of which are 

 short and of irregular form. Sometimes there are so many of these 

 groups that the basal system of rhizoids resembles the root-stock 

 of Neottia ; and in other cases it appears as if the plant were 

 arising from a mass of cells. In later stages these bushy branches 

 break up into separate cells. It is possible that they serve for the multi- 

 plication of the plant. Certainly this function belongs to the primary 

 rhizoid, which in middle and old age develops stolons, and may bear 

 numerous young plants. Adventive rhizoids arise from older vegetative 

 filaments— Wille calls these " strengthening-rhizines " (" Verstarkungs- 

 rhizinen "), and divides them into extracuticular and intracuticular. 

 These are here discussed. Finally, the author remarks on the extra- 

 ordinary power of reproduction and multiplication possessed by Clado- 

 phora glomerata, which may take place in six different ways ; and he 

 describes the best methods for preparing and staining material for 

 examination. 



Growth of Fucus.* — P. Hariot makes a communication on the 

 growth of species of Fucus. These algse, together with species of 

 Melobesise, are largely used for manure on the western coasts of France, 

 but they may only be collected at certain seasons, according to law. The 

 author has therefore made some experiments as to their rate of growth, 

 both for scientific and economic interest. At Tatihou, in November 

 1908, he scraped clean two rocks covered with F. vesiculosus and F. platy- 

 carpus. One of these rocks was easy to observe at low tide, being in the 

 outer port, while the other was further out. One of the harbour walls 

 was also scraped. , The ^denuded rocks became covered at first with a 

 layer of green algse, Ulva and Enteromorpha ; and only when these had 

 come to an end, about six months after the scraping, did young plants of 

 Fucus begin to appear. On July 9 the young shoots on the nearer rock 

 were 5-6 mm. high, while those of the other rock were 3-4 mm. high, 

 and on the harbour wall there were no algas of any sort. The tufts 

 of Fucus cut off close to the rock did not begin to shoot again till 

 January. Further observations will be made and the results published. 

 In the meantime, the author draws the conclusion that the growth of 

 Fucus is slow. 



Laminarise of the Mediterranean.!— G. Zodda publishes some notes 

 on the species of Laminaria which occur in the Mediterranean, which 

 only amount to four, namely, L. Rodriguezii Born., which is endemic, 

 a doubtful record of L. digitata, L. saccharina, and L. bulbosa. On the 

 latter species the author makes a few remarks, discussing the form medi- 

 terranean which is considered by authors to be merely a juvenile form 

 of Saccorhiza bulbosa, or, as the author prefers to call the species, 

 Laminaria bulbosa. He points out that the sporangia occur both on 



* Comptes Rendus, cxlix. (1909) pp. 352-4. 

 t Nuov. Notar., xx. (1909) pp. 94-9. 



