ANATOMY OF THE GENUS SALICORNIA. 339 
cell, where these outgrowths are cut across a large rounded opening appears 
(text-fig. 11). 
The tubular outgrowths serve to connect up the loosely arranged cells in 
such a manner as to provide the largest possible intercellular air space 
system. The tissue thus described differs in various details from that of any 
aerenchyma previously recorded. It approaches that figured by Schenck * 
for Epilobium hirsutum, but differs in the more regular arrangement of the 
rows of cells and in the method of connection of the rows one with another ; 
in the latter feature it recalls Jussieua peruviana. On the whole the tissue is 
intermediate between the two types described by Schenck. The tubular 
outgrowths on the aerenchyma cells of Salicornia closely resemble those 
described by Schenck Т as occurring on the * Markstrahlzellen” of the 
secondary phloem in the aerotropic roots of Laguncularia racemosa, 
In all the cases in which aerenchyma was developed in the species of 
Salicornia, it was completely surrounded by a thin layer of cork. Since the 
material was not collected until September it seems unlikely that the 
aerenchyma, in the annual forms at any rate, ever becomes freely exposed, 
as is the case in so many plants in which the tissue is produced. А similar 
feature is recorded by Wittet as occurring in Lysimachia vulgaris, L. In 
Salicornia europea, in which the development of the tissue reached the 
maximum dimensions, the outer tissues are very readily torn off, and in 
cutting sections it is almost impossible to retain them in position (PI. 16. 
fig. 14). S. ramosissima shows a development of the aerenchyma in ribs 
on the stem. 
We have throughout given the name of aerenchyma to this air storing 
tissue of Salicornia, in agreement with the definition of the tissue given by 
Taberlandt§, Goebel|, and Gerschon Seliber f], though according to 
Schenck ** the name should be restricted to an aérating tissue formed from 
a cork cambium. 
* Schenck, П.: “Uber das Aérenchyma, ein dem Kork homologes Gewebe bei Sumpf- 
pflanzen." Pringsh. Jahrb. f. wiss. Botanik, Bd. xx. Berlin, 1889, pp. 526-574, pl. 25-28. 
+ Schenck, Il. : “ Über die Luftwurzeln von Avicennia tomentosa und Laguncularia race- 
mosa.” Flora, 1889, Heft 2, p. 88. 
i Witte, H. : * Über das Vorkommen eines aérenchymatischen Gewebes bei Lysimachia 
vulgaris, L?” Kjell. Bot. Studier, Uppsala, 1906, p. 265. 
& Haberlandt, G.: Physiologische Pflanzenanatomie, Leipzig 1896, p. 382. 
| Goebel, K.: Pflanzenbiologische Schilderungen. П. Marburg 1891, p. 256. 
© Gerschon Seliber: * Variationen von Jussieua repens mit besonderer Berücksichtigung 
des bei der Wasserform vorkommenden Aérenchyms.” Abh. der Kais. Leop.-Carol. Deutsch. 
Acad. der Naturforscher, Bd. 84, Halle 1905, p. 43. 
#* Schenck, H.: Pringsh. We. eit. p. 927. 
