ON THE SELF-FERTILIZATION OF PLANTS. 263 



HENSLOW ON THE SELF-FERTILIZATION OF PLANTS. 



This paper ^ is elaborate, mostly able as well as ingenious, 

 in all respects considerable, and unconvincing. Its thesis is 

 the Darwinian "Nature abhors perpetual self-fertilization," 

 read backward. It concludes that, " not only are the majority 

 of plants self-fertilizing, but that those which are exclusively 

 so propagate abundantly and with extraordinary rapidity, are 

 best able to establish themselves in foreign countries, as, be- 

 ing quite independent of insects, they run no risk of exter- 

 mination on that score ; . . . that, so far from there being 

 any necessarily injurious or evil effects resulting from the 

 self-fertilization of plants in a state of nature, they have 

 proved themselves to be in every way the best fitted to sur- 

 vive in the great struggle for life." The hypothesis is also 

 advanced " that they are all degraded forms," and that there- 

 fore " their ancestral life-history is a longer one than that of 

 their more conspicuous and intercrossing relations." We fail 

 to see how this follows, except upon the assumption that the 

 earliest phaenogamous plants had the most highly organized 

 blossoms ; and that would not accord with vegetable palaeon- 

 tology. 



Mr. Henslow rejoices that he has one stanch supporter ; 

 " for, as has been seen, Mr. T. Meehan has arrived at the 

 same conclusion ; " and indeed he builds not a little upon 

 facts supplied by Mr. Median's observations. He cites the 

 latter's " admirable paper, which was rej^roduced in the 

 ' Gardner's Chronicle ' for September 11, 1875, and is in fact 

 an ' apology ' for self-fertilization." As he then marshals 

 twenty reasons for believing particular plants to be normally 

 self-fertilizing, and nineteen " chief facts which may be re- 

 garded as occurring correlatively with self-fertilization, some 

 being actual causes which directly or indirectly bring it about," 

 it would appear that it is no longer self-fertilization, but 



1 On the Self-Fertilizaiion of Plants. By George Henslow ; Transactions 

 Linnpean Society, 2 ser., Bot. i. London, 1879. (American Journal of 

 Science and Arts, 3 ser., xvii. 489.) 



