The cells of an\' li\inii tissue of the hark nia\- dixide (luring 

 the formation of intumescences. Normal mitotic division 

 figures occur throughout. An increase of about 35 percent in 

 the number of cells was found to occur in outgrowths in the 

 ends of cuttings. 



Calcium oxalate crystals are usually very abundant among 

 the free cells of an intumescence, and are ai)parently a by- 

 product of the solution of the cell walls. 



The thin-walled hypertrophied cells, which make up the 

 major portion of the swollen mass of the intumescences, usually 

 contain two or more large \acuoles. The cytoplasm between 

 these ^■acuoles makes the cells appear to be divided by cross- 

 walls. These cells may li\'e for several weeks after becoming 

 free. 



A protecti\'e cork la>'er generally forms along the inner 

 margin of an intumescence and separates it from the normal 

 tissue below. This layer when present limits the spread of the 

 swellings. When conditions are favorable for the de\'elopment 

 of the swellings the cork layer may fail to form. 



Arthur H. Graves, 



• Secretary. 



FIELD TRIPS 



Flowers Late This Spring 



Members of the Torrey Botanical Club, on field trips in 

 May, in the Ramapo section of the Palisades Interstate Park, 

 found the trees and flowers very late in putting forth leaves and 

 blossoms this spring. Cypripediiim parviflorum, which Mr. 

 L. F. Logan expected to show his part>^ on May 13, had not 

 appeared above ground, and C. acaiile which ordinarily is in 

 bloom by May 5, was just emerging. This party was a large 

 one, numbering twenty-two, the route being from Tuxedo, 

 over the Tuxedo-Mount Ivy Trail to Lake Sebago, then down 

 Stony Brook, and back to Tuxedo. Purple trillium was in 

 prime, two weeks late, and Marsh Marigold was still in bloom. 

 Four of this party, led by the chairman of the field committee, 

 who branched off and followed the .Suffern-Bear Mountain 

 Trail to Suffern, had an exciting ad\enture. They ran into a 



85 



