224 BOTANICAL GAZETTE [SEPTEMBER 
alveolar cells of the middle region. At the time of fertilization, the upper 
and lower portions of the endosperm consist of small-celled tissue, while the 
middle portion is alveolar. Sequoia is regarded as a connecting link 
between Gnetum and the angiosperms on the one hand and between gymno- 
sperms and the archegoniates on the other. 
In a later paper 3 he has described the archegonia and pollen tubes of the 
same species. The archegonia are very large, and some sections show as 
many as sixty. They sometimes occur singly, but are often grouped. In 
development they resemble the archegonia of the Cupressineae, since they 
are often in direct contact with each other and do not form any ventral canal 
cell. There are no proteid vacuoles. The neck consists of two cells, in this 
respect resembling the older gymnosperms. 
e pollen tube grows through the nucellus, not between the nucellus 
and integument, as described by Shaw. At the time of fertilization the 
pollen tube contains the two male cells of equal size, and two small nuclei, 
one of which is the tube nucleus and the other “the nucleus of the cell which 
united the generative cell with the microspore wall.” The general structure 
of the pollen tube and its contents agrees with the Cupressineae. ‘The 
morphological considerations, together with the geographical distribution, lead 
to the conclusion that Sequoia is nearly related to the ancient type from which 
the modern Araucarias and Cupressineae have descended. CHARLES J. 
CHAMBERLAIN. 
CONNECTING THREADS which establish protoplasmic continuity between 
adjacent cells have been studied by Mr. Hill‘ in the embryo and seedlings 
of Pinus pinea and in the mature tissues of P. si/vestris, Some attention was 
also paid to the endosperm of P. pizea. The endosperm consists chiefly of 
rather large rounded cells, but a close examination shows that in many cases 
an internal division has occurred. The threads are evenly distributed in 
the young walls, but are grouped in the older walls. Near the cotyledons 
the cells are smaller, the threads thicker, and there are traces of ferment 
action. Ferments from the cotyledon pass into the endosperm through the 
threads, and by the same route food materials pass from the endosperm to 
the embryo. 
In the seedling the absorptive side of the cotyledon is more abundantly 
supplied with threads than the side not exposed to the endosperm. There 
ee W.: Beitrage zur Morphologie und Entwickelungsgeschichte einiger 
spermen, II. Ueber die Corpuscula und Pollenschliauche bei Seguota semper 
P 9 
ae Bull. des Natur. de Moscow. ls. 10-11. 
LL, A. W.: The distribution and character of connecting threads in the 
rag a Pinus silvestris and other allied species. Phil. Trans. Roy. Soc . London 
B. 194 : 83-125. pls. 37- 
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