372 BOTANICAL GAZETTE fay 
formation. WASIELEWSKI (85) and WISSELINGH (g1) have dis- 
cussed the question of amitosis in various tissues. Miss DALE 
(13, 15) found that in certain intumescences caused by abnormal 
light, heat, etc., oil is formed in place of starch, the nuclei become 
club-shaped and highly refractive, and the nucleoli are often 
increased in number. Amitosis was found to be almost universal, 
and formed nuclei of unequal size. Von SCHRENK (67a) described 
similar intumescences due to chemic stimulation. Other studies 
upon the structure of intumescences were made by SoRAUVER (71, 
72) and STEINER (73). The structure and the pathologic modifica- 
tions of chromatophores have been studied by Kister (39) in 
Ceramium cells, where under various influences they may be con- 
tracted into drops or flattened out into irregular bands. NEMEC 
(55) has reported the decrease in the number of chromosomes in 
old tissue, and their increase in hypertrophied cells. Besides these 
already enumerated, it would be well to note the following as 
articles dealing with several phases of the subject, and containing 
valuable lists of references: ZIMMERMAN (96, 97), WARD (87), 
UNGER (81), FarrcHitp (21), and N&mec (60). Some abnormal 
nuclear phenomena have been described also by MIEHE (442) 
near wound tissue, Kont (36) in cells under the influence of aspara- 
gin, and ZACHARIAS (95) under various influences. 
Summing up the results so far obtained in the study of the 
effects of parasitic invasion and abnormal physiologic influence 
upon the histologic and cytologic elements of plants, we find that 
the various kinds of tissues, collenchyma, parenchyma, scleren- 
chyma, and cork, may be abnormally developed or repressed; cell 
walls may be simply perforated, or much thickened and more or less 
changed in constitution; secondary cell formation may arise; nuclei 
and nucleoli may be increased or reduced in number and size, and 
variously deformed; chromatin may likewise be increased or de- 
creased; the cell sap may acquire a new color; the starch and calcium 
oxalate content may change; and the chromatophores changed in 
appearance and efficiency. 
Methods 
For the investigations to be reported here the ordinary methods 
of preserving the material were used. The medium solution of 
