110 THE AMERICAN BOTANIST 



tunate. Normally it is a tendrid-climber like the grape to 

 which it is near allied, but on occasion it may develop adhesive 

 disks and it frequently put out roots like the poison ivy. No- 

 body seems to have investigated the subject to see if the three 

 methods of climbing indicate three forms of the plant. 



Coal from Plant Spores. — A writer in a recent issue 

 of Rhodora reports that certain coals that have been investi- 

 gated, consist almost entirely of the microspores and mega- 

 spores of certain fern allies that flourished during the coal 

 forming period. By careful manipulation of the coal it is 

 possible to study the spores satisfactorily with the miscroscope. 

 These spores are the next thing to pollen grains — pollen 

 grains themselves being essentially spores — and the bitumin- 

 ous matter found in some coals is regarded as produced from 

 the waxy matter contained in the spore coats. 



Fruits Ripened by Chemicals. — The ripening of fruits 

 is essentially a chemical process. Everyone is familiar with the 

 fact that even the sweetest fruits may be sour or astringent 

 until they are nearly ripe. When they are full grown, or "full' 

 as the grower often expressed it, a gradual change occurs. The 

 tannin, starches and other constituents of the fruits are slowly 

 turned to sugars by a process akin to digestion in animals if, 

 indeed, it is not exactly like it. This being the case many ex- 

 periments have been undertaken to advance or retard the ripen- 

 ing process. In fruits, such as the banana, that have to go a 

 long way to market, they are usually picked before they are 

 ripe and, since they will carry best in the green condition, no 

 effort is made to hurry their ripening. On the contrary the 

 ripening process is retarded. At the end of their journey, how- 

 ever, it is often desirable to ripen them at once. This is ac- 

 complished in some fruits by exposure to the sunshine, or by 

 heating. A writer in Science mentions a new and very suc- 

 cessful method which consists in exposing the green fruits to 



