[KrrscH] CERTAIN STRUCTURES IN THE PTERIDOPHYTES All 
STRASBURGER, EDUARD. 
(19) Histologische Beitrage, Heft III., 1891. Ueber den Bau und 
die Verrichtungen der Leitungsbahnen in den Pflanzen. 
(20) Manual of Vegetable Histology. 
TERLETZKI, P. 
(21) Anatomie der Vegetationsorgane von Struthiopteris germanica 
Willd. und Pteris aquilina L. Mit Tafel XXIV., XXVI. Jahrb. 
wiss. Bot. Bd. XV., 1884. 
THOMAE, K. 
(22) Die Blattstiele der Farne. Hierzu Taf. V.-VIII, Jahrb. wiss. Bot. 
Bd. XVII., 1886. 
THOMÉ, OTTO W. 
(23) Text-Book of Structural and Physiological Botany. 
WATT, GEORGE. 
(24) A Plague in the Betel-Nut Palms and The Destruction of the 
Tissues by What appears to be a Form of Thyloses. The Agri- 
cultural Ledger, 1901, No. 8. 
WEISS, F. E. 
25) On the Thyloses of Rachiopteris corrugata. The New Phytologist, 
Vol. V., No. 4, Apr. 1906. 
WILLIAMSON, W. C. 
(26) On the Organisation of the Fossil Plants of the Coal-measures. 
Part Vibe 
Phialrans Sita Vol 
(20) Ditto, Part XX Phill Trans, 1880) Vol. 171 
(28) On Some Anomalous Cells developed within the interior of the 
Fossil Plants of the Coal-Measure. Ann. of Bot. I. 
EXPLANATION OF ABBREVIATIONS ON ILLUSTRATIONS. 
A. tr. Disorganised annular tracheids of the protoxylem. 
C. Intercellular canal or remnants of it. 
Ph. Phloem. 
Prx. Persistent protoxylem. 
Sp. tr. Disorganised spiral] tracheids of the protoxylem. 
‘Th. Thy loses. 
W. Par. Wood parenchyma. 
Xy. Xylem. 
Photo 1.—Pteris aquilina, stipe, May 29th, 1899. Canal filled with disorgan- 
ised protoxylem elements. XX 200. 
Photo 2.—Pteris aquilina, stipe, May 29th, 1899. Longit. Formation of canal 
by disorganisation of spiral and annular tracheæ. X 230. 
Photo 3.—Same as Photo 2. Showing canal formed and disorganised proto- 
xylem floating in it. X 200. 
