1885.1 NEW-YORK MICROSCOPICAL SOCIETY. 7 



CRITICISMS ON J. KRUTTSCHNITT'S PAPERS^ 



AND PREPARATIONS' RELATING 



TO POLLEN-TUBES. 



BY N. L. BRITTON. 

 {Read November 2isi, 1884.) 



When a theory having no well-ascertained facts on which to 

 base its arguments is persistently forced on the scientific com- 

 munity, it becomes the duty of some one to refute the ideas thus 

 advanced and, if possible, prevent their further circulation, to 

 the end that those who are less well-provided with opportunities 

 for study may not be deceived into forming erroneous conclu- 

 sions, or into doubting abundantly proved theories. As the 

 Special Committee on Phanerogamic Botany for this Society, I 

 have thought it my office to assume such task. 



It has been sought by Mr. J. Kruttschnitt to show that dur- 

 ing the process of fertilization of the ovules in Phanerogamic 

 plants, the pollen-tubes which extend from pollen-grains resting 

 on or attached to stigmatic surfaces, do not enter the ovules in 

 the manner described in all recent treatises on Vegetable Physi- 

 ology, but that the protoplasmic contents (fovillse) of the grains 

 reach the embryo-sac in some other way ; and he suggests** that 

 "the pollen-tubes discharge their contents amongst the papillae 

 of the stigma, * * * * thus carrying down the substance 

 of the pollen only j * * * * the ovule is fertilized by ab- 

 sorbing the contents of the pollen-grain." 



The mounts which Mr. Kruttschnitt has made and distributed 

 consist of vertical and horizontal sections through ovaries, and 

 longitudinal sections through stigmas and styles. This method 

 of examination is not as satisfactory as that of picking the ovary 

 open with a needle at the critical time. What is to be gained 

 from horizontal ovarian sections is not apparent. The distribu- 

 tion of hundreds of such slides will have no effect on the opinion 

 of the well-informed student. It is not stating the case too se- 

 verely to say that his preparations indicate nothing whatever in 

 proof of his theory ; whatever evidence they bring is purely 

 negative, and therefore unsatisfactory. His ideas are, indeed, 



lAm. Month. Micros. Journ., June, 1882 ; Sept., 1883. 



2Am. Postal Micros. Club, special box No. 4, issued Oct. 16, 1884, and previously 

 distributed slides. 

 .,,-3 Am. Month. Micros. Journ., 1883, p. 166. 



