November 



1885.] 



SCIENCE. 



465 



DR. ASA GRAY'S JSEVENTY-FIFIH 

 BIRTHDAY. 



The seventy-fifth anniversary of the birth of 

 Dr. Asa Gray occurred on the 18th of November. 

 At the suggestion of the editors of the Botanical 

 gazette, many of the botanists of North America 

 united in presenting to the foremost botanist of 

 the country a token of love and esteem in the form 

 of a silver vase. 



This vase was presented on the morning of the 

 18th, without formahty. It is about eleven inches 

 high, and is appropriately decorated with those 

 plants which are distinctively American, and which 

 are most closely associated with Dr. Gray. The 

 place of honor on one side is held by Grayia poly- 

 galoides, and on the other by Shortia galacifolia. 

 Among other?. Aster Bigelovii, Solidago serotina, 

 Lilium Grayi, Centaurea Americana, Notholaena 

 Grayi, and Rudbeakia speciosa, are prominent. The 



workmanship is highly artistic, as well as remark- 

 ably accurate, and reflects credit upon the designers, 

 Messrs. Bigelow, Kennard, & Co., of Boston. 



The vase stands oa a low ebony pedestal, which 

 is surrounded by a silver hoop, bearing the inscrip- 

 tion, — 



1810 — November eighteenth — 1885. 

 Asa Gray, 

 in token of the universal esteem 

 of American botanists. 

 The greetings, by card and letter, of the one 

 hundred and eighty contributors, were presented 

 on a plain but elegant silver tray. They con- 

 tain the warmest expressions of esteem and grati- 

 tude. 



In the afternoon Dr. and Mrs. Gray received, 

 quite informally, many of their friends. 



A NEW SYSTEM OF OYSTER-CULTURE. 



The hope that I might solve, or help to solve, 

 the oyster-problem practically, has served to 

 constantly encourage me for the fi.ve years that I 

 have been w^orking v^ith that object in view. In 

 the belief that what I now have to offer presents 

 one of the only possible practical solutions of the 

 oyster-question, I submit it to the oystermen of 

 our country as a method by the help of which 

 they may be enabled to rear an abundance of 

 ' seed ' upon areas which are positively and ab- 

 solutely under individual, proprietary control. 

 The first principles of the new method are given 

 below, and it will be seen that they include or 

 embrace all that it has been proposed to accom- 

 plish by the use of any other plans hitherto pro- 

 posed ; that is, it is proposed to utilize the three 

 dimensions of a body of water, moved automati- 

 cally back and forth in a canal by the tides, for 

 the purpose of spat-collecting. In such a canal 

 an enormous amount of cultch or collecting sur- 

 face will be exposed to the fry, diffused through- 

 out the three dimensions of the surrounding water, 

 during the spawning season. In tliis way the 

 maximum amount of spat can be obtained with a 

 minimum expanse of water. 



The first principles of the new method of spat 

 or 'seed-culture,' which I here propose, are the 

 following : — 



1. Oyster embryos diffuse themselves through- 

 out the three dimensions of a body of water, and 

 will affix themselves to collecting surfaces similarly 

 distributed, up to and even above low-water level. 



2. The floating fry will adhere to smooth sur- 

 faces as well as rough ones. 



3. The surfaces upon which spatting occurs 

 must be kept as free as possible from sediment and 

 organic growths, in order that the very tiuy yoimg 



