No. 3,] BOTANY AND ZOOLOGY. 181 



while self fertilization is in most cases not absolutely prevented^ 

 it is generally rendered very difficult. Many species, however, 

 which are ordinarily cross-fertilized never open their flowers when 

 the weather is cold and rainy, and are, in such circumstances j, 

 necessarily self-fertilized. In grasses with unisexual flowers, 

 cross-fertilization must take place as a matter of course. In 

 those with hermaphrodite flowers a few are protogynous, and 

 hence also necessarily cross-fertilized. In the larger number of 

 grasses, however, the male and female organs are developed at 

 the same time, and special contrivances occur for ensuring cross- 

 fertilization. In the rye the position of the organs is such thafc 

 a part of the pollen from one flower must almost necessarily fall 

 on the stigma of another flower. In the wheat each separate 

 flower remains open only for an extremely short time, the glumes 

 separate from one another suddenly, the anthers immediately 

 protruding, and a large quantity of the pollen is dispersed into 

 the air, the whole process not occupying more than half a minute. 

 In most of these cases the stigma remains receptive only for a 

 very short period and then dies, while in others the stigma re- 

 mains in a receptive condition till long after the anthers have 

 dropped ofi", and then must necessarily be open to the access of 

 foreign pollen. In comparatively few cases the natural contriv- 

 ances appear to favor self- rather than cross-fertilization. Thus 

 in the oat and barley the majority of the flowers never open, and 

 are, therefore, necessarily self-fertilized ; there appear, however, 

 in almost all cases to be a small number of flowers, often arranged 

 in one or two separate rows, which do open, and therefore may 

 introduce occasional cross-fertilization. It is probable that the 

 same species behaves difi'erently in relation to its arrangements 

 for fertilization under difl'erent circumstances of climate, while 

 species very nearly related exhibit phenomena which ofi"er a 

 marked contrast. — American Naturalist. 



Sphagnum and Hypnum Peat. — The opinion seems to have 

 been somewhat prevalent that peat does not accumulate abun- 

 dantly in limestone regions, but this is not true of large portions 

 of some of the northern interior states. For example, all the 

 peat of Iowa is in an eminently limestone region, and the water 

 taken out of any of the marshes shows a strong reaction for lime 

 by proper chemical tests. 



From my own observations I believe that Sphagnum peat does 



