COLLECTING AND PRESERVING MATERIAL. 407 



green, in pairs, 5-10 cm. long; cones small, about 5 cm. long, 

 the ends of scales bearing a conspicuous protuberance, long and 

 recurved on the basal scales. The Austrian pine, also widely 

 planted, has dark green longer leaves (10-15 cm.), larger cones, 

 with no recurved bosses. The flowers are of two sorts and 

 should be watched for in spring (May) as new shoots appear. 

 The staminate flowers form conspicuous yellow clusters at the 

 base of the young shoots, and should be collected as soon as the 

 sporangia begin to shed the spores. The pistillate flowers are 

 quite inconspicuous, small oval clusters (5-7 mm. long) pro- 

 jecting slightly beyond the tip of the young shoots. The tree 

 bearing staminate flowers usually bears few pistillate ones, and 

 vice versa. Collect shoots bearing each kind of flowers, cutting 

 far enough back to include the leaves of the previous year. Pre- 

 serve in alcohol or formalin. Collect also year-old and two-year- 

 old cones. Preserve the former (green) in fluid; the latter 

 (mature) dry. 



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. Preserve flowers and leaves in 

 summer in alcohol or formalin. 



Stems. — The various sorts recommended may be collected at 

 any convenient time and preserved in fluid. 



Seeds. — The most useful seeds for laboratory work are Indian corn, 

 wheat, buckwheat, castor bean {Ricinus), white lupine, (Lupinus al- 

 bus), scarlet runner {Phaseolus), broad bean {Vicia /aba), hemp, 

 white mustard. These should be obtained fresh each year, as they 

 deteriorate more or less with age. Those which cannot be had 

 everywhere (such, perhaps, as lupine, castor bean, scarlet 

 runner, and broad bean) may be purchased of seedsmen in large 

 cities. See advertisements in magazines. 



Potted plants. — Such as are grown in window gardens or all 

 greenhouses will suffice. A commercial greenhouse, if accessi- 



