BOTANICAL GAZETTE. 



stance remaining of the egg adhering to them as a while 

 opaque mass. 

 74 hrs. the same as the last except the substance on the tentacles 



has turned brown. 

 91 " the marginal tentacles were all reflexed except those on one 

 side where they were held by the viscid substance men- 

 tioned above. 

 98 hrs. all the submarginal tentacles, for at least one half the cir- 

 cumference, standing at an angle of 90° with the blade. 



137 hrs. the tentacles were nearly all reflexed, and tho«e that were 

 not were sunply held back by the remaining substance of 

 the egg. 



148 hrs. the leaf was expanded but somewhat stuck together in parts by 

 remains of egg ; the leaf seemed almost lifeless ; the tenta- 

 cles were shrunken and with no secretion ; however, the 

 remainder of the phiut seemed to be in a more thriving eondi- 

 tion than at the opening of the experiment. 



186 hrs. the substance on the leaf had become fibrou'^; leaf fully 

 expanded; no secretion. 



195 hrs. the leaf on one side was so covered with the fibrous substance, 

 mentioned in the last note, as to ajjpear quite dead. 



220 hrs. the leaf was. ajjparentb , rapidly dying. 



316 " the leaf was completely dead and covered with a mold,* 



An Easily Made Observation. — Several years since I con- 

 structed a coujile of simple machines for measuring the longitudinal 

 growth of ])lants which were so effective for work and so easily made 

 withal that it may be well to describe them for the benefit of pupils 

 who may wish to make some experiments. They were essentially the 

 same as the arc indicator descriljed by Sachs in his Text Book. My 

 arc indicators consisted of square pieces of manilla pai:)er tacked to 

 suitable frames ; upon these arcs were descrilied and divided into 

 spaces of 5° each. At the centers small pulleys made of perfectly 

 round sections of corks were placed and so arranged as to revolve 

 with the utmost ease. By properly fastening a strip of manilla paper 

 to the large square piece, the cork pulley was easily held in place 

 by a pin passing through the strip and exactly through the center of 

 the cork and the center of the arc, the pin turnmg in the paper su])- 

 ports, but l)eing fixed in the cork. To the cork a delicaie finger made 

 from a straight "splint" of a common corn broom, was attached to 

 serve as an index. A silk thread to be attached to the plant whose 

 growth was to be observed was wound once around the pulley, and to 

 the free end a weight heavy enough to little more than counter-bal- 

 ance the index, was attached. 



It took but little longer to make these two instruments than it has 

 taken me to describe them. I immediately put them in place twelve 

 inches or so above a couple of young bean seedlings [Phaseoliis ^\i.) 



*The i^ame as the mold r^pok-u of iu a pvcvious toot-note. 



