76 MICROSCOPIC OBJECTS. 



remain in a hot and dry atmosphere without losing their 

 moistm*e. The form and arrangement of the Stomata 

 vary in different plants. The Catalogue contains a Hst 

 of the most diversified cuticles, both with and without 

 stomata. — Magnifying power 80 to 150 diameters. 



Flours. — The meal or flour of grain and other seeds may 

 be distinguished from each other by the microscope. To 

 facihtate these researches, specimens of known quahties 

 should be mounted and labelled, so as to be ready for 

 comparison with any specimen to be examined. 



Hairs, Down, Pili, Cilia, 8fC. of Plants. — These appen- 

 dages usually grow upon the leaf, but are not confined to 

 any particular part. In the plants which produce cotton 

 (Gossypium herlaceum, SfC.J, the hairs are attached to and 

 envelope the seeds. Hairs are composed of cellular 

 tissue. Their functions are said to be either lymphatic or 

 secreting. They oifer great varieties in form ; hence they 

 are much admired as microscopic objects. The stellated 

 hairs upon the leaf of the Deutzia scahra, when viewed in 

 situ by reflected hght under a power of 30 to 60 diame- 

 ters, are highly interesting. When separated by a lancet 

 from the leaf, and mounted as transparent objects, they 

 resemble minute star-fishes fAstericeJ. The hairs of the 

 Stock GiUiflower fMatthiola incanaj are forked and lie 

 parallel to the leaf, supported in the middle by short foot- 

 stalks. These are said to be divaricated. The cellule 

 which forms the footstalk is supposed to be an elevated 

 part of the cuticle. 



Hairs are sometimes branched, as on the petioles of 



