58 



The final germinating capacity thus did not decline seriously 

 from autumn to spring; but the germinating energy in 5 days fell 

 off very significantly. 



BETULA PAPYRACEA appears, on the other hand, to lose its 

 germinating capacity more quickly, since two germinating tests in 

 the spring of 1912 with Canadian seed, harvested in 1911, resulted 

 as follows: 



5 10 20 days 



February germination 22 63 67 / 



May germination 27 34 



BETULA LUTEA, likewise of Canadian origin, germinated much 

 more slowly, viz. 5 days 0; 10: 25; 30: 36.5, and 80 days 47 %. 



PLATANUS OCCIDENTALS serves as a very good example 

 to show of what great use the germination tests can be. 



According to this, every second year the seed germinates not 

 at all or only very badly, which leads to the conjecture that 

 American collectors only have a good harvest in alternate seasons, 

 when they supply themselves for two years. 



GARY A, JUGLANS and QUERCUS. Besides the species which 

 are set forth in Table IV, I have also weighed the following species 

 to find out the number of seeds per kilogram. 



Weight of 1000 Number of 

 seeds in grams seeds per kg 



Carya alba Nutt 37004058 200 



amara Nutt 4148 200 



microcarpa Nutt. 3400 300 



olivaeformis Nut t. 2500 400 



porcina Nutt 4600 200 



sulcata Nutt 14000 100 



tomentosa Nutt . 6390 160 



