248 Stockard : Nectar-glands of Vicia Faba 



Further, I wished to determine what connection or relation exists 

 between the nuclear and cytoplasmic changes and to find what 

 constituent of the nucleus should it prove to be active in the 

 process is most concerned. The observations described below 

 are designed to attack these questions, though it is recognized 

 that the results rather indicate the need of further careful and ex- 

 haustive study than give definite answer to these queries. 



METHOD AND MATERIAL 



The nectar-glands on the stipules of Vicia Faba are beautifully 

 adapted for study ; since from the terminal bud to the old mature 

 leaves may be obtained all stages in the development of these 

 glands as well as the entire cycle of secretory action. The living 

 material flourishes in the greenhouse during winter, so that prepar- 

 ations may be made from time to time with little trouble. . 



Realizing that the methods of fixation and staining in work of 

 this type are open to so much criticism, I have taken all practical 

 precautions against errors from this source. First, observations 

 as far as possible on nuclear positions et cetera were made upon 

 free-hand sections of the living glands, and in the second place a 



large number of fixing and staining solutions were used and the 

 results compared. 



The glands were cut from the stipules with a border of non- 

 glandular tissue, thus insuring the presence of all parts of the 

 gland in the preparation, and further facilitating a comparison be- 

 tween gland-cells and ordinary tissue-cells. The material was then, 

 while in the natural condition, quickly placed in the fixing fluids ; 

 those employed being Gilson's fluid, picro-acetic, chromo-acetic, 

 picro-corrosive, picro-aceto-sulphuric, alcohol acetic, sublimate 

 acetic, and picro-sulphuric, with the following success. The 

 Gilson's fluid gave most satisfactory preparations, the nucleus and 

 cyptoplasm being in apparently perfect condition. The picro- 

 acetic and chromo-acetic gave fairly good results, and the picro- 

 corrosive used by Reed also proved favorable though inferior to 

 Gilson's fluid. Picro-aceto-sulphuric was rather uncertain, though 

 in some cases fairly good preparations were obtained by its use. 

 Alcohol acetic, sublimate acetic, and picro-sulphuric were all un- 

 favorable. The series for study was then fixed with Gilson s, 



