19161 HOBTICULTUEE. 741 



impermeable seeds were viable except in the seed of C. nicitam. The average 

 percentage of viability of the impermeable seeds was invariably greater than 

 of the seeds which softened within six days. 



In an experiment to determine the average rates of softening of seeds which 

 had remained impermeable after ten days in wet blotters, less than 10 per 

 cent of the seeds of red clover, alsike clover, white clover, and sweet clover 

 softened in one month, and from about one-third to a little over one-half of 

 them softened in three years when kept in wet blotters. Nearly all of the im- 

 permeable seeds of alfalfa, hairy vetch, okra, and crimson clover softened in 

 one year, but a very few of all except crimson clover remained impermeable 

 after three years. 



In dry storage nearly all impermeable seeds of alsike clover, white clover, 

 and sweet clover remained impermeable from two to three years. Impermeable 

 red-clover seeds became permeable gradually In dry storage, but it was found 

 that from one-third to two-thirds may still be impermeable after four years. 

 Impermeable clover seeds thoroughly matured before harvesting as compared 

 with similar seeds not so well matured softened and germinated more slowly 

 under conditions favorable to germination and also became permeable more 

 slowly in dry storage. 



Among other methods of treatment reported it was found that alternations 

 of temperature caused the softening and germination of many impermeable 

 clover seeds when a temperature of 10° C. (50° F.) or cooler was used in alter- 

 nation with a temperature of 20° or warmer. The effect of these alternations 

 was greatly increased by previously exposing the seeds to germination con- 

 ditions at 10° or cooler and was decreased by previously exposing the seeds 

 to germination conditions at 30°. 



Even under the most favorable conditions only a small proportion of imper- 

 meable seeds of red clover, alsike clover, white clover, and white sweet clover 

 was found to produce seedlings promptly when sown in warm weather, and it 

 was also observed that such seeds will pass the winter in the soil in a freezing 

 climate without injury. The impermeable seeds of these species when placed 

 in wet blotters softened and germinated more slowly than similar seeds of 

 alfalfa, crimson clover, hairy vetch, and okra. All germinated within one year 

 in some cases, while in others over 50 per cent were still impermeable after 

 four years. It is stated that a large proportion of impermeable alfalfa, crimson 

 clover, okra, and hairy vetch seeds will germinate in the soil during the first 

 few months after planting, but that nearly all alfalfa and okra seeds, even if 

 impermeable in the fall, are killed when they pass the winter in soil or on 

 the plants out of doors in a freezing climate. Suggestions for the use of imper- 

 meable seeds are included. 



HORTICTJLTTJKE. 



The garden book, V. D. Davis (New York: Orange Judd Co., 1915, pp. Vin+ 

 244, pis. 7, figs. 47). — A popular treatise on the growing of vegetables under 

 both home and market conditions. 



The small garden, J. Schneideb (Der Kleingarten. Leipsic and Berlin: B. O. 

 Teubner, 1915, pp. 95, figs. 80).— A. practical treatise on the propagation, cul- 

 ture, and care of fruits, vegetables, and flowers in the home garden, with special 

 reference to German conditions. 



The fruit growers' yearbook and market gardeners' guide, 1916 (London: 

 The CaUe Printing & Publishing Co., Ltd., 1916, pp. 112, figs, y).— This year- 

 book contains a monthly working calendar for indoor and outdoor fruit growing 

 in England, a review of the previous year's fruit and vegetable prices at CJovent 



