24 CONNECTICUT GEOL. AND NAT, HIST. SURVEY. [Bull. 



rows of green cells, which play a part in holding the central 

 portion of the capsule in place. Of course the stomata aflford 

 a communication between the air space and the outside air. 



As the spores mature, the photosynthetic tissue breaks 

 down, the columella shrivels, and the spores eventually lie 

 loose in an enlarged cavity, bounded by little more than the 

 epidermal layer of the capsule wall. In a few of the simpler 

 genera the capsule bursts irregularly at maturity. In the 

 majority of cases, however, it splits by a circular line in the 

 upper part, which cuts off an apical portion, or Hd, from the 

 capsule proper. Sometimes the region of splitting is marked 

 by a row of modified epidermal cells, called an annulus, but 

 this is not always developed. The walls of the annular cells 

 have the power of absorbing water readily and swelling, thus 

 forcing the lid to separate. After the lid has fallen away, 

 the mouth of the capsule usually appears fringed with a circle 

 of pointed teeth called a peristome, and in many genera two 

 peristomes are developed, an inner and an outer. The inner 

 peristome is always more delicate than the outer, and its 

 divisions, when present, are called segments, instead of teeth. 

 The segments are sometimes separated from one another by 

 one or more delicate hair-like structures known as cilia. The 

 peristome plays a peculiar part in the scattering of the spores ; 

 in moist weather the teeth come together and close the mouth 

 of the capsule ; in dry weather they separate and allow the 

 wind to scatter the spores. Although the description just 

 given will apply to the majority of cases, the structure of 

 the capsule may be much simpler or even more complex than 

 indicated. Taking the Bryales as a whole, the sporophyte 

 shows the highest type of development to be found in the 

 Bryophytes. It does not, however, show unlimited growth, 

 the entire capsule maturing at the same time, and in this 

 respect it is surpassed by the Anthocerotales. 



The Bryales are divided by Brotherus into more than forty 

 families, about half of which are represented in Connecticut. 

 These are based on the general habit and structure of the 

 gamctophyte and on the peculiarities of the capsule, many of 

 the most important characters being derived from the 

 peristome. The species flourish best in moist and shaded 



