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sufficient to call forth the formation of protonema. The 

 protonema production frora the costal region occurred through- 

 out the entire extent of the leaf, but the number from the 

 apical portion was greater than that from the basal portion. 

 The defoliated stems produced protonema direct, through- 

 out their entire length, and they were not confined entirely 

 to the leaf axil, any of the surface cells being capable of 

 growth. The defoliated stem generally produced at least 

 one new shoot , and sometimes this originated from the very 

 base of the stem , sometimes from nearer the apex. The 

 whole plants placed in exactly the same conditions produced 

 protonema direct from the stem, and also new shoots. 



CERATODON PÜRPUREÜS. 



All attempts to obtain protonema from the leaves of 

 Ceratodon were without effect. The leaves were kept for 

 several months in apparently vigorous condition without any 

 sign of protonema formation. The defoliated stems are however 

 able to give rise to an abundant protonema growth, which 

 originates direct from the region of the leaf axils. Khizoids 

 are also produced but they very soon became protonema in 

 nature in the cultures which are exposed to light. In the 

 dark the growths were more of a rhizoid nature and gener- 

 ally remained almost devoid of branches. The protonema 

 production was not local but was general throughout the 

 entire length of the stem. The defoliated stems also produced 

 new shoots as lateral branches. The point of origin was 

 not definite, since they might come at any point between 

 the base and apex of the stem. The production of new 

 shoots occurred as well in darkness as in light. Whole plants 

 placed in the same conditions as the defoliated stems , pro- 

 duced new lateral shoots and quite a number of protonema, 

 hence the protonema and shoot production was not called 

 forth by defoliation. 



3* 



