MISCELLANEOUS PLANTS 



189 



tion and an abundance of fresh materials would be needed before 

 one could discuss this important point. 



In the table subjoined are incorporated the results of the author's 

 flotation experiments on the upper joints of different species of 

 Cakile from several regions. It may be inferred from the data 

 there given that the floating powers may vary considerably even in 

 the same species. In two of the columns the results are applied to 

 the transport by currents. A drifting rate of fourteen miles a day, or 

 one hundred miles a week, is taken as representing the usual distance 

 that would be covered under favourable conditions. 



Cakile Flotation Experiments 



Results of experiments by the author on the floating capacity in sea-water of the 

 upper joints of the fruits of different species of Cakile. (See explanation above 

 given.) 



Species of Cakile 



Locality of 

 Collection 



Flotation Period 

 in Days 



Capacity for 

 Transport by Cur- 

 rents stated in 

 miles at the rate 



of 14 miles a 

 day, or 100 miles 

 a week 



Age of the Fruits 

 when collected 



Aver- 

 age 



Maxi- 

 mum 



Aver- 

 age 



Maxi- 

 mum 



C. maritima . 



Cornwall 



7 



10 



100 



140 



Recent 





Cornwall 



7 



9 



100 



130 



Seven months 





Devonshire 



7 



10 



100 



140 



Recent 



C. lanceolata 



Jamaica 



25 



35 



350 



500 



Recent 





Turks Islands 



3 



5 



40 



70 



Recent 





Turks Islands 



5 



7 



70 



100 



Fifteen months 



C. edentula . 



Azores 



9 



12 



130 



170 



Recent 



The number of fruits experimented on ranged from six to fifteen. The term " re- 

 cent " is applied to fruits that were experimented on at periods varying from a few 

 weeks to two or three months after they had been gathered in the dry state from the 

 plant. 



Additional Experiments. 



The buoyancy in sea -water was also tested in the case of some fruits (upper joints) 

 of the following species very kindly sent to the author by Dr. Millspaugh. As they 

 had been collected several years before, and since only three fruits could be used in 

 each experiment, it seemed best to separate the results from those given above. The 

 maximum results obtained for the flotation period were as follows — 



Cakile americana from Lake Michigan 5 days. 

 C. edentula from Lake Michigan 12 days. 

 C. alacranensis from the Alacran Shoals 20 days. 

 C. fusiformis from Dog Key, Mississippi 21 days. 



Canavalia obtusifolia, DC. 



This creeping or climbing plant has established itself on the beaches 

 of the warm regions of the globe, for instance, on the Pacific and Atlan- 

 tic coasts of tropical America, on both the east and west shores of 



