ii6 ROBERT BROWN 



of the " immediate agent derived from the male organ, or the 

 manner of its application to the ovulum in the production of 

 that series of changes constituting fecundation." But he puts 

 forward the opinion that a more attentive examination of the 

 process in Orchids and Asclepiads is more likely to be fruitful 

 of results than most other families. 



He returns again to this matter of fecundation in the following 

 year, studying several orchids, but especially Bonatea, for the 

 purpose. He is somewhat shaken as to the validity of his 

 former inferences, and concludes that the " mucous cords " (i.e. 

 strings of pollen tubes) are perhaps derived from pollen " not, 

 however, by mere elongation of the original pollen tubes, but by 

 an increase in their number, in a manner which I do not attempt 

 to explain." In this later paper he also hazards the suggestion 

 that in Ophrys, as impregnation is frequently accomplished 

 without the aid of insects, "...it may be conjectured that the 

 remarkable forms of the flowers in this genus are intended to 

 deter, not to attract, insects." Also he suggests that the insect 

 forms in orchidaceous flowers resemble those of the insects be- 

 longing to the native country of the plants. This is a clear 

 foreshadowing of what is now called protective mimicry and 

 the former suggestion is not at any rate wholly without modern 

 supporters, though Brown's share in its origin seems not to be 

 generally recognised. 



The keen desire to get to the bottom of a problem, which 

 was so outstanding a feature of Brown's whole mental attitude, 

 unquestionably explains why he was led to make so many 

 important discoveries in such widely different directions. His 

 first hand knowledge of the structure of a vast number of plants 

 gave a soundness and depth to his morphological investigations 

 that must arouse the admiration of everyone who is acquainted 

 with them. He was never satisfied with perfunctory attempts 

 to solve a problem, but, as we have already seen, in the example 

 of his studies on Asclepiads and Orchids, he would return again 

 and again to the matter till he had satisfied himself of the 

 accuracy of his work. It is a pity that all of the present day 

 botanists do not follow more closely in his steps in this respect. 

 Publication of a paper seems to some to be a matter of greater 



