MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. II5 



indicative of the earlier, or initial stages of formation of periderm. 

 On June 17 one stem had attained a height of 36 cm. the longest 

 internode measuring 8 cm. 



The normal stems of the age of the etiolated showed a brown 

 color at the base due to the death of the epidermal cells. Five or 

 six layers of cork had been formed underneath, and the thick-walled 

 cortex contained much chlorophyl, especially in the outer layers. 

 Crystals were numerously distributed throughout this tissue. A- 

 heavy cambium layer was present, and the incomplete ring of bast 

 consisted of cells which had undergone extreme thickening. All 

 of the parenchymatous cells were heavily loaded with starch. 



A cross section of the basal portion of the etiolated stem that had 

 begun to turn brown showed the epidermal system in a fairly normal 

 condition with the walls white and translucent. The usual forma- 

 tion of cork in the hypodermal region was lacking, but a median 

 region in the cortex had begun to collapse, the walls assuming a 

 brownish hue giving the external color to the stem. The entire cor- 

 tical region had thinner walls than in the normal and both starch and 

 crystals were noticeably less abundant than in the normal. In this 

 as well as in Cornus and ^lercus, the lack of cork formation in the 

 hypodermal region was accompanied by the development of a phel- 

 logen immediately external to the cylinder of bast cells, some- 

 times in immediate contact with the collapsed layer : the bast fibers 

 were nearly normal in stature so far as might be seen in cross sec- 

 tion. A distinct layer of primary cambium could not always be 

 made out, and the walls of the wood cells were not so heavy as in 

 the normal. The above collapse of the median region of the cortex 

 was accompanied, or followed, by the shrinkage of the basal portion 

 of the stem in such a manner that it had a smaller diameter than the 

 terminal portion, a phenomenon also seen in ^lercus. 



Hicoria ovata (Mill) Britton. 

 Nuts of Hicoria ovata placed in the soil in the control chamber, 

 and the dark room on October \6, 1901, had begun to germinate on 

 January 4, 1902. On April 16, one young plant with two primitive 

 leaves was seen in the control chamber, the stem being about 8 cm. 

 long above the place of insertion of the cotyledons. The lower part 

 of this stem bore a few bract-like leaves. Two seedlings were 

 found in the dark room. One had sent up a main stem about 25 



