256 Stockard : Nectar glands of Vicia Faba 



COMPARISON WITH OTHER OBSERVATIONS 



■ 



Co nparing the above changes with those observed in various 

 gland-cells it is difficult to agree in all points with any one author, 

 but on the other hand a study of the results forces one to recog- 

 nize that secretion in the cell is a process that may be accomplished 

 in many different ways. To quote the statement made in An 

 American Text-book of Physiology, on this subject, by Howell : " In 

 the sebaceous secretion the cells seem to break down completely 

 to form the material of secretion ; in the formation of mucus by 

 the goblet-cells of the mucous membrane of the stomach and intes- 

 tines a portion of the cytoplasm after undergoing a mucoid degen- 

 eration is extruded bodily from the cell to form the secretion ; in 

 the mammary glands a portion of the substance of the epithelial 

 cells is likewise broken off and disintegrated in the act of secretion, 

 while in other glands the material of the secretion is deposited 

 within the cell in the form of visible granules which during the act 

 of secretion may be observed to disappear, apparently by dissolu- 

 tion, in the stream of water passing through the cell. Facts like 

 these show that some at least of the products of secretion arise 

 from the substance of the gland-cells and may be considered as 

 representing the results of a metabolism within the cell-substance. 

 From this standpoint, therefore, we may explain the variations in 

 the organic constituents of the secretions by referring them to the 

 different kinds of metabolism existing in the different gland-cells.' 

 This statement relating to animal secretion might with slight altera- 

 tions be applied equally well to that of plants. 



It is now pertinent to consider some of the later contributions 

 to the cytology of secretion among plants and animals and compare 

 the results indicated with the case at hand. Mathews ('99), work- 

 ing on the pancreas cell of various animals, observed the following 

 facts. He found that these cells contained in their basal portions 

 a ball of thread-like fibers which is termed pancreatic mitosome, 

 or " Nebenkern." During secretion these threads, which extend 

 into the upper portions of the cell, break up into the granules which 

 finally form the secretion-substance. The fibrils were found in a 

 number of cases to terminate in, or over, the peripherally placed 

 chromatic masses of the nucleus. Thus Mathews concluded for 

 this and other reasons that the nucleus was passive in the actual 



