CLARK: RECENT CRINOIDS 425 



salt solution every fourth day (ordinary water being used in 

 addition for any further moisture needed by the plant) from 

 August 31, 1914, to January 20, 1915. At this latter date the 

 foliage was yellowing and the roots were beginning to decay. 

 Other plants of this species, however, which were given small 

 amounts of normal salt solution from time to time, actually 

 made better growth than those not receiving any salt. 



POSSIBLE UTILIZATION OF KIGERUKKAN FOR STOCKS 



When we remember that the orange is one of the most sensitive 

 to alkali among the fruit trees, it can readily be seen that Merope 

 angulata is a plant of decided interest for trial as a stock for 

 other citrous plants, and experiments are now being carried on 

 under greenhouse and field conditions to determine whether 

 it can be so used. So far Citrus has not been grafted success- 

 fully on this stock; but a seedhng kigerukkan grafted on a seedhng 

 grapefruit grew rapidly and after some months flowered, having 

 developed a strong swelling at the point of union of the stock 

 and scion in the meantime. It is therefore hoped that recipro- 

 cal grafting of the kigerukkan and the cultivated species of 

 Citrus will ultimately be successful. 



ZOOLOGY. — The relationship between phylogenetic specialization 

 and temperature in the recent crinoids.^ Austin H. Clark, 

 National Museum. 



In a previous paper- I discussed the relationship between 

 phylogenetic specialization and bathymetrical distribution in the 

 recent crinoids. In the present paper I shall consider in the 

 same way the relationship between phylogenetic specialization 

 and the temperature of the habitat. 



Unfortunately temperature records for the crinoids are com- 

 paratively few, and for many of the families very unsatisfactory; 

 yet, incomplete as they are, they bring out certain features which 

 are not without interest. 



" Published by permission of the Secretary of the Smithsonian Institution. 

 2 Journ. Wash. Acad. Sci. 5: 309-317, May 4, 1915. . 



