328 IOWA ACADEMY OF SCIENCE Vol. XXV, 191S 



which has hypoggeoiis germination. George B. Enierson^° makes 

 a very general statement about the germination of the maples, 

 implying spring germination and that the dormant period is 

 five or six weeks. The statement in regard to germination under 

 natural -conditions is incorrect. 



Of the exotic maples Lubbock states that the seedlings of the 

 Sapindacese studied by him came under three types. The coty- 

 ledons of Cardiosperraum, the balloon vine, fall early, showing 

 M transition between the hypogteous and epiga^ous germination. 

 The Acer Pseudo Platanus is epigaeous with 5-nerved strap- 

 shaped cotyledons. The Saphidus inaequalis has hypogseous ger- 

 mination. 



Acer saccharinum L. Silver or Soft Maple. The germina- 

 tion of this species has been frequently described. Asa Gray^^ 

 in his structural Botany describes the germination of Acer sac- 

 charum, Acer ruhrum and the Horse Chestnut, accompanying 

 his descriptions with the well known classical figures. Lub- 

 bock^^ describes seedlings of a number of species of Acer. A 

 study of the germination and vitality of seeds, kept under dif- 

 ferent conditions, was made by L. H. Pammel and C. M. King,^^ 

 in which it was found that seeds of this species soon lost their 

 vitality when subjected to dessication ; that the vitality could be 

 prolonged by keeping the seeds in a refrigerator at a low tem- 

 perature. In such cases, after twenty-three days of drying, the 

 seeds dropped from 75 per cent to 6 per cent •<l germination, the 

 germination being distributed over a period of seventeen days. 

 The germination of freshly gathered seeds when mature and 

 kept moist proceeds after a few days. In the case at hand the 

 percentage was 75, germination being distributed over a period 

 of twenty- two days. 



Seeds of the silver maple were collected for study, May 19, 

 1917, when they were falling from the trees, just four weeks 

 from date of bloom, ::\Iay 1, 1917. Fresh seeds placed in a moist 

 chamber, in laboratory, germinated 98 per cent in five days. 

 Seeds placed in moist sphagnum moss to simulate natural con- 

 ditions, geraiinated 100 per cent in five days. Seeds dried in the 

 laboratory atmosphere for two weeks and tlum placed in damp 



^"Report on trees and shrubs of Massacluisetts growing naturally in the 

 forests of Massachusetts, p. 482. 



siThe elements of Botany, Rev. Ed., p. 17, /. 21-2G, 1887 and Structural 

 Botany, 1.5-17. 20, /. ll-2o, 36-39. 



^^Some contributions to our knowledge of seedlings, 1. pp. 360-365. 



^^Delayed germination: Proc. Iowa Acad. Science, Vol. 17. pp. 31-33. 



