1908] POND—LATERAL ROOTS 4II 
8 2 the numerous figures of VAN TrecHem and DovuLioTs any 
of corrosion of cell walls or actual evidence of digestion. ‘The 
do not show the stratum of compressed and collapsed cells 
surrounds the young lateral root, at least in the cases of Lupi- 
nus albus and Vicia Faba. 
abe heer the same general conclusion as to the 
Re ct Re of the lateral root was expressed by REINKE.* The 
a. INKE are more accurate than VAN TIEGHEM’s, as in 
oak. : Be 9, the layer of distorted and collapsed cells which sur- 
ae young lateral root is shown. Still the figures do not 
evidence of digestion. 
ah on VAN TieGHEM but later than REINKE, VONHONE* 
:...., : eertialt the relative importance of mechanical pressure 
fo. : activity in the emergence of endogenous organs. His 
:... « (p. ge that the young lateral root secretes a substance 
eine ces, e cortical tissue and digests it, just as does the 
‘tas ed by the embryo of a seed digest its endosperm. 
Sil = pe notes that the passage of lateral roots through 
ae re . purely mechanical, though aided perhaps by 
, ae on the part of the cortical tissue. 
ee ot . ae is study of the penetration of living tissue by the 
aes th la and Pisum, found that the root mechanically pushes 
y through the various tissues tested. ‘The results of CzaPEK*® 
ce PEIRCE, since the former was unable to find any evi- 
iastatic or of inverting ferments in the excretion of the 
3V 
AN TrecHEM, Pu., ET Dovutiot, H., Recherches comp 
des me 7 , 
™m * Fe 
bres endogénes dans les plantes vasculaires. Ann. Sci. 
1660. pls. 1-40. 1888 
aratives sur l’origine 
i. Nat. Bot. VII. 8: 
iiber Wachsthumsgeschichte und Mor- 
sTEIN’s Bot. Abhand. Gebiet Morphol. 
4 
a.” JOHANNES, Untersuchungen 
bad P . der Phanerogamen-Wurzel. HAN 
hysiol. 1321-38. 1871. 
, H. von, Ueber das Hervorbrechen endogener 
ane, Flora 63:227-234, 243-257, 268-274- 1880. 
5 VONHO» Orga: 
— SNE ne aus dem 
6p 
Konig} cache W., Druck- und Arbeitleistung durch wachsende Pflanzen. Abhand. 
<i achs. Gesells. Wiss. 203:235-474- 1893- 
aig PERE GEO. J., Das Eindringen von Wurzeln in lebendige Gewebe. Bot. 
Asrgagie 1894. 
oe Czarex, Frreprics, Zur Lehre der Wurzelausscheidungen. 
*32I-390. 1896. 
Jahrb. Wiss. Bot. 
