628 EXPERIMENT STATION RECORD. 



ruinating gas upon the flowering carnation, the authors have carried on some ex- 

 periments, which are described in detail, to determine the effects and toxic limits 

 of illuminating gas and ethylene on the buds and flowers of the carnation. In 

 a later paper they expect to describe in detail the effects of illuminating gas and 

 its main constituents upon the vegetation of the carnation. 



The authors found the flowers of the carnation to be extremely sensitive to 

 traces of illuminating gas in the air. With the varieties Boston Market and 

 pinlv Lawson, 3 days' exposure to 1 part in 40,000 Ivills the young buds and 

 prevents the opening of those already showing petals. In tlie same varieties 

 1 part gas in 80,000 causes the closing of the open flowers after 12 liours' 

 exposure. This injury takes place directly on the bud or flower exposed and 

 not indirectly through absorption by the roots. The so-called " sleep " of the 

 carnation is probably often caused by traces of illuminating gas in the air. 



Ethylene is even more fatal to the flowers of the carnation. Three days of 

 exposure to 1 part in 1,000,000 prevents the opening of buds just showing the 

 petals, and 12 hours' exposure to 1 part in 2.000,000 causes the closing of flow- 

 ers already open. There is apparently evidence to indicate that the toxic limit 

 of illuminating gas upon these flowers is determined by the ethylene it contains. 



As yet no chemical test has been found that is delicate enough to detect the 

 least trace of illuminating gas that will cause injury to carnations. 



The viability of seeds, J. J. Thornber (Plant World, 11 (1908), No. 7, pp. 

 138, 159). — Observations are reported on the viability of seeds after continuous 

 prolonged submergence. The experiments were conducted at the Arizona Ex- 

 periment Station and were suggested liy the conditions which obtain in the 

 valley of the Colorado River in southwestern Arizona, which is subject to an 

 annual rise in May and June following the melting of the snows in the moun- 

 tams near its source. There is practically no rainfall in this section, and annual 

 crops are grown by sowing seed on the flood plains before the season of high 

 water begins. 



In the experiments noted, the seeds were sown in soil in the usual manner and 

 flooded to a depth of 12 in. for a period of 38 days, which is about the period of 

 average submergence over the lower flood plain of the Colorado River. With 

 this treatment the ijercentages of germination of nomual seeds were as follows: 

 Bermuda grass 42, Johnson grass 45, amber cane 45, wild hemp (Sesbania 

 macrocarpu) 75, Japanese rice 36, Honduras rice 23, and sugar beets 16. No 

 germination resulted with oats, rye, corn, millet, or Jerusalem corn after more 

 than a few days' submergence. Where the period of submergence was extended 

 to 50 days, the percentages of germination were: Bermuda grass 14, Johnson 

 grass 23, amber cane 45, Honduras rice 23, and wild hemp 13. Of radish, ruta- 

 baga, sugar beet, and tomato seed, 100 per cent germinated after being under 

 water for 21 days, cabbage and celery seed 75 per cent, and watermelon seed 33 

 per cent. In the latter instance the seed was not placed in the soil. 



On the longevity of seeds, A. J. Ewart (Proc. Roy. Soc. Victoria, n. ser., 

 21 (1908), No. 1, pp. 1-210, pis. 2). — A study has been made of a large number 

 of seeds, ranging from fi'esh seeds to those known to be GO or more years old, 

 to determine their germination. In all, more than 3,000 tests were made, 

 embracing many species and genera. The results of the teste are given in 

 alijhabetical lists, and with these are incorporated all the previous records 

 that the author was able to A-erify or correct. 



In summarizing the tabulated results, the author divides seeds into 3 bio- 

 logical classes, according to their duration of life under optimal conditions. 

 These are short-lived or microbiotic seeds whose duration does not exceed 3 

 years, mesobiotic seeds which may last 3 to 15 years, and macrobiotic seeds 

 which may last from 15 to over 100 years. 



