278 



MacMillan : Ouservatioxs on Nereocystis 



the leaves rarely come to exceed fifty feet in length. This meas- 

 urement of the leaves much exceeds that given by Mertens in his 

 letter to his father published by von Chamisso in the 1829 volume 

 of Linnaea. Mertens gives twenty-seven feet as the extreme leaf- 

 length and Oliver, quoting no doubt from this original account by 

 the discoverer places the leaf-length at eight meters. We have, 

 however, leaves nearer fifteen meters in length than eight. A 

 hundred meters as the extreme length of a mature individual, \he 

 figures given by Kjellman in the Engler-Prantl Naturpfianzenfami- 

 lien, is not at all excessive. Of this at least eighty meters would 

 belong to the stipe, two or three meters to the elongated retort - 

 shaped pneumatocyst and the remainder to the laminae. ' 



The breadth of mature lobes of the lamina is from 8 to 12 cm., 

 the diameter of the stipe is from 8 mm. to 2 cm. just imder the ' 

 pneumatocyst area, the pneumatocyst is sometimes 15 centimeters 

 in diameter just below the attachment of the lamina and the 

 branches of the hapterc-clustcr range from 3-5 millimeters in 

 diameter. These measurements are all conservative and larger in- 

 dividuals may no doubt be found. 



When first formed the pneumatocyst is spherical and retains 



this shape in plants 30 cm. 



long. 



Later it becomes ovoid and 



then piriform. In a plant 30 cm. long the pneumatocyst is one 

 centimeter in diameter. In a plant 50 cm. long the pneumatocyst 

 is 2.5 cm. in diameter and 3 cm. in length. After the plant has 

 attained a length of 3 or 4 meters the pneumatocyst begins to 

 elongate and from that stage until maturity maintains the charac- 

 teristic retort-shaped appearance finally becoming 2 or even 3 



meters in length, in which condition, as long ago noted by 



Mertens, it is employed by the Aleutians to siphon water from 

 their canoes. By the same tribes, Mertens also observed that the 

 stipe is employed for fishing lines. As learned by Miss Tilden 

 such lines are still preserved as curiosities by a few native fisher- 

 women, but ordinary tackle is generally in use. 



Reproductive Area 



The only functional reproductive bodies 



known to occur in Nercocyst's are the spores, formed in sporano-ia. 



ogether with the paraphyses these sporangia produce large soral 



patches on both sides of the leaf A sorus may be as much as a 



meter in length, from i-j cm. in width, and on a single leaf three 



