COLLECTING AND PRESERVING MATERIAL. 29I 



male and female organs are in the same cluster, at the apex of 

 the axis. Under the microscope the species may be recognized 

 by the orange inner peristome with double rows of perforations 

 in the membrane below the segments. Preserve as directed for 

 Porella. Almost any similar moss will serve equally well, espe- 

 cially the common species of Bryum, 



Adiantum. — Gametophytes of any fern will answer. They are 

 flat green heart-shaped bodies 2-5 mm. in diameter, attached to 

 soil by rhizoids. They may be collected on fern pots or grown 

 in greenhouses, or may be obtained from supply company named. 

 Especial care should be taken to have some young sporo- 

 phytes still attached to gametophytes. The sporophytes of 

 the maidenhair fern are easily recognized by the peculiarly 

 branched leaf. The stem is wholly underground. Each leaf 

 has a slender polished stalk which forks into two equal 

 branches ; these fork, one branch of each pair growing straight 

 and bearing leaflets while the other again forks in the same way ; 

 and so on until 4-8 branches have been formed on each half. 

 Collect underground stems and roots, loosening them gently and 

 washing oft dirt carefully to avoid destroying all root tips and 

 hairs. Preserve these in alcohol or formalin. Gather leaves 

 when the crescent-shaped fruit dots at edges of leaflets are yel- 

 lowish brown (August). Preserve by drying, spreading out 

 each leaf to show its mode of branching clearly. 



Caltha. — This plant is common in wet meadows and swamps 

 northward. It is 15-30 cm. high, smooth, with rather coarse 

 hollow ribbed stems, orbicular or kidney-shaped alternate leaves, 

 with broad clasping base to the petiole, and numerous bright 

 yellow flowers 20-25 mm. in diameter, produced for two weeks 

 or more in April or May. Gather entire plant; wash the roots. 

 Preserve a few plants and an extra supply of flowers and fruits 

 in alcohol or formalin. Dry most of the entire plants. 



Lathyrus. — The sweet pea is grown in almost every flower gar- 

 den and is known everywhere. Flowers and leaves of as great 

 variety as desired may be preserved at the proper season in 

 summer in alcohol or formalin. Or, simple flowers may be se- 

 cured at greenhouses. 



Stems. — The various sorts recommended may be collected at 

 any convenient time and preserved in fluid. 



Seeds. The most u seful seeds for laboratory work are Indian corn . 



wheat, buck wheat, castor bean (i?zVi«»j), white lupine, (Z«/j«Kf«/- 



