KOTES ON SARCOMENIA MINIATA AG. 283 



the tetraspores at the top show signs of division. This explains 

 readily the extreme usefulness of such arrangements as tend to 

 consolidate the stichidia. 



The cells of the central tube are connected by a very strong 

 strand of protoplasm. The contents of these cells are much more 

 delicate than those of the pericentral tubes, but by the help of this 

 considerable strand of protoplasm they are always easily recognized. 

 Secondary pores and smaller strands of protoplasm connecting the 

 pericentral tubes with each other or with the central tube were also 

 visible. 



I believe I saw migrating cells as described by Kolderup- 

 Rosenvinge" for Polysiphmia, but I failed to detect a cell-nucleus 

 in the little particles of protoplasm that were lying in the gelatinous 

 layer between the cells. I must therefore leave the question un- 

 settled whether these particles of protoplasm are identical with 

 Kolderup-Rosenvinge's migrating cells. 



The branching of Sarcowenia viiniata is very irregular ; the 

 branches arise, as Agardh has already described, from the middle 

 of the stem. Careful examination shows that they are the result of 

 endogenous growth, as described already by Falkenberg f and 

 Ambronn]: for species of the genera Bijtipldcea, Vidalia, Amansia, 

 and Polyzonia. The central tube pushes a branch between the peri- 

 central tubes, which yield to let the young unicellular branch pass. 

 This cell divides by horizontal walls, tlie first two segments re- 

 maining naked, the upper ones surrounding themselves in the usual 

 way by pericentral tubes. The pericentral tubes of the stem from 

 which the branch arose give off a few cells that cover the first naked 

 segments of the branch, but otherwise they undergo no further 

 changes. 



On one specimen only of my whole collection could I detect 

 antheridia. The plantlet bore also cystocarps ; it is therefore 

 monoecious. The antheridia were found at the base of the stem, 

 and consisted of very small leaflets, borne in the usual endogenous 

 way. The lateral tubes of these leaflets are, as in the case of the 

 branches bearing tetraspores, the cells out of which the propagating 

 organs arise. I have not been able to follow the mode of develop- 

 ment from lack of specimens, but figs. 6 and 7 are exact figures of 

 the antheridia as I saw them. I can only suppose that each cell of 

 the lateral tube divides first by a horizontal wall, and that the 

 protoplasmic masses (cf. the figure) seen at the base of a large empty 

 cell are the remnants of the lower or pedicel cells, whose function 

 it probably was to prevent the collapsing of the walls of the cells 



* Kolderup-Eosenvinge, L., " Sur la formation de spores secondaires chez 

 les Pohjsiphonia," Bot. Tidskr. 17 Bd. 1 Heft. Kopenhagen, 1888. 



t Falkenberg, " Ueber endogene Bildung normaler Seitensprossen in den 

 Gattungen Rytipltla'a, Vidalia, und Aman>iia,'^ Nadir, dcr Ges. d. Univ. zu 

 Gdttingen, 1869, p. 285. 



I Ambronn, "Die Art und Weise der Sprossbildung bei den Rhodomeleen 

 Gattungen Vidalia, Amanda, und Polyzonia,'" Verhandl. d. bot. Vereins d. 

 Frovinz Brandenburg, 1880, p. 74. 



u 2 



