194 CARNEGIE INSTITUTION OF WASHINGTON. 



No results of analyses can as yet be given, but it is believed that a thorough 

 examination of this practically untested field can not fail to yield results that 

 may hold the highest interest not only in the domain of physiological chemistry, 

 but also in their bearing upon the question of the organic origin of some of the 

 great ore deposits of the world. 



Report on Bahama Cerions planted on the Florida Keys, hy Paul Bartsch. 



The colonies near Miami were visited on June 18, 1915, but on account of 

 the great number of mosquitoes on the keys it was impossible to make a proper 

 examination and it was found necessary to return to Miami. On June 19 we 

 returned to the keys and examined the colonies carefully. It was found that 

 of the 50 tips of the first generation of Florida-grown "White House type" 

 cerions planted on the outside of the north end of Sands Key last year, only 

 a single specimen, about half-grown, was to be found. It is probable that 

 most of the planted specimens survived and were not far away from the planting, 

 but buried in the sand, for it was found in later visits that in places from which 

 every visible si)ecimen had been gathered, on the following day more mollusks 

 were found clinging to the bushes in plain sight. The explanation was that 

 the adult shells were probably buried in the coarse sand of the beach and that 

 the scratching about and disturbing of this caused them to come to the surface 

 during the night. On the first Ragged Key north of Sands Key we collected 

 46 of the originally planted "White House type" cerions and 23 adult speci- 

 mens of the first generation of Florida-grown individuals, together with 45 

 young, varying in size from a quarter-grown to almost adult. The 23 speci- 

 mens were carefully measured and photographed and replanted on June 21, 

 about 50 feet north of the original planting, on the same sand ridge and in line 

 with the landing stage. On June 21, when the original planting was again 

 examined, 47 additional specimens were found under and upon several clumps 

 of bushes which I had looked over quite carefully on the 19th; 16 of these were 

 marked individuals from the original planting and 13 were adults of the first 

 generation of Florida-grown specimens. These we marked by cutting scratches 

 into the ribs with a knife and then planted them with the 23 in the new location. 

 The 18 half-grown individuals we left with the original planting. 



On the second key north of Sands Key, 76 adults of the first generation of 

 Florida-grown individuals of the "King's Road type" were found, which were 

 carefully measured, photographed, marked, and planted on the same key, 

 about 70 feet south of the original planting, on the same sand ridge on which 

 the original planting was made. We marked the place by cutting off the tops 

 of the small bushes growdng near the place of the planting. 



Owing to the very poor conditions of the colonies last year on Tea Table Key 

 and Indian Key, we did not stop to examine these this year. 



On June 23 we visited the colonies on Bahia Honda. Here we found 56 full- 

 grown individuals of the first Florida-grown generation and 23 ranging from 

 quarter-grown to almost full-grown, but none of the originally planted speci- 

 mens seem to have survived a fire which had visited this place. Most of the 

 specimens found were in a ditch that appears to have escaped the fire. The 

 adults were photographed, and all but one, which was reserved for further study, 

 were marked and planted on the seaward side of the ditch, about 50 feet east 

 of the coconut palm. We marked the place ^\^th a blue stake. 



On the same day we visited Duck Key, where we found 46 of the originally 

 planted specimens and 7 Florida-grown individuals of the first generation, a 

 little less than half-grown. We left all of these in the old planting. This key 

 has become so heavily overgrown with tall grass, Sporoholus grandis, that the 

 cerions may not survive, since the grass appears to j^roduce conditions much 



