STRUCTURE AND DEVELOPMENT OF THE SHOOT IN DOLICOTHELE

DARLINGTON, H. T., and G. P. STEINBAUER. (Michigan State U., East Lansing.) The eightyyear period for Dr. Beal's seed viability experiment. Amer. Jour. Bot. 48(4): 321-325. 1961.Seeds of 20 species of plants were buried 80 years ago on the Michigan State University campus. Bottles have been dug up periodically in the intervening years and the seeds tested for viability. A bottle representing the 80-year period of burial was dug up this spring and the contents distributed uniformly on the surface of sterilized soil in the greenhouse. Of the 20 species whose seeds were buried in 1879, only 3 have survivors as viable seeds. These are the same 3 that had survived the 70-year burial period, namely: curled dock, Rumex crispus; evening primrose, Oenothera biennis; and moth mullein, Verbascum blattaria. The low percentage survival of curled dock (2%) indicates that the longevity of the buried seeds of this species is nearing the end. The situation is more favorable for evening primrose, with 10% survival. The third, moth mullein, has about as many survivors as 10 years ago, a remarkably high figure of 70% viability. Since there has been no significant drop in viability of the buried seeds over the last 30 years, it seems highly probable that longevity of buried seeds of this species may extend over a century. A brief summary is given of the current status of the behavior of buried seeds, based on this and other buried seed experiments. THE SPRING of 1960 marked the 80-year period for the seed-viability experiment initiated by Dr. W. J. Beal in the autumn of 1879 at East Lansing, Michigan. On April 18 of this year, the 12th bottle was dug up, leaving 8 more still buried. The techniques adopted for germination have been similar to those in previous tests. The nature of this experiment is best indicated by Dr. Beal himself: "I selected 50 freshly grown 1 Received for publication September 19, 1960. Published as Paper No. 60-21 from the Department of Botany and Plant Pathology, Michigan State University, and Jour. Ser. Paper No. 2679, Michigan Agri. Exp. Sta., with approval of the Director. The writers wish to express their appreciation of the assistance given by Mr. H. Bockstahler in carrying out the seed viability tests in the greenhouse. 2 The senior author has made the tests on this, experiment during the period from 1915 to 1951. In this paper, he has written only that portion indicating the general nature and scope of the experiment while the junior author is responsible for the general discussion as it applied here. seeds from each of 233 different kinds of plants. Twenty such lots were prepared with a view of testing them at different times in the future. Each lot or set of seeds was well mixed with moderately moist sand, just as it was taken from 3 ft. below the surface where the land had never been plowed. The seeds of each set were well mixed with the sand and placed in a pint bottle, the bottle being filled and left uncorked and placed with the mouth slanting downward so that the water could not accumulate about the seeds." The bottles (each containing 1000 seeds) were buried in a row approximately 18 in. below the surface of the ground (see fig. 1, Darlington, 1931). The seeds, as shown in table 1, were those of 20 common weeds growing in the vicinity of East Lansing. 3 The first account of the experiment (1905) mentioned 2 tree species, Quercus rubra and Thuja occidentalis, neither of which survived even up to 1884, the date of the first test. This content downloaded from 157.55.39.163 on Wed, 21 Sep 2016 04:49:13 UTC All use subject to http://about.jstor.org/terms