THE AMERICAN BOTANIST 79 



any ledge upon which they may chance to settle. When such 

 reef-building was reputed to be exclusively the work of corals, 

 the Bermudas were assumed to be largely of animal origin, 

 but now they are said to be principally the remains of plants.' 

 The lime-secreting algae are able to thrive deeper in the sea 

 and in colder waters than the corals find agreeable and thus 

 we may account for various coral reefs outside the regions in 

 which corals are active at present. Since the occurrence of 

 reefs has often been depended upon to indicate various geologi- 

 cal changes, it is likely that our ideas of these, too, will have 

 to be modified in the light of these recent discoveries. Here- 

 after reefs will have to be distinguished as coral reefs and 

 coralline algae reefs. 



LiPARis IN Cook Co., Illinois. — On June 18th, 1912, I 

 had the good fortune to find quite a colony of Liparis liliifolia, 

 consisting of about 20 individuals, on the bluffs which border 

 Lake Michigan in the vicinity of Glencoe. Aside from the 

 size of the colony, the most remarkable thing about the plants 

 was their surprising vigor, which was well illustrated in the 

 great number of flowers to each inflorescence. The seventh 

 edition of "Gray's Manual" states the number of flowers to 

 each stalk as being from five to fifteen, but three of the largest 

 examples taken from this colony had 25, 37 and 39 flowers 

 each, and there were many with over 15 flowers. — Edzvin D. 

 Hull, Chicago. 



Coronas and Pollen. — Under exceptional weather con- 

 ditions either the sun or moon may be surrounded by small 

 circles known as coronas. The commonest form of corona is 

 caused by the sun or moon shining through thin clouds of 

 water drops, though similar phenomena may be produced by 

 ice particles in the upper air, or even by clouds of dust driven 

 out of volcanoes. According to Scientific American the plants 

 may on occasion play a part in forming coronas. A French 



