Environment and Adaptation 225 



bly thus disseminated. The slimy spore masses of 

 the Phalloidese, a family of large fungi, have an 

 excessively offensive odor which is said to attract 

 carrion-loving insects, which are the disseminators 

 of the spores which adhere to their bodies. It is 

 among the angiosperms, however, that the most 

 perfect instances of these adaptations are found. 



Cross-pollination by Insects. While there has 

 lately been a tendency to minimize the importance 

 of insect aid in the pollination of flowers, and to 

 explain otherwise their remarkable color devices and 

 structures, there can be no question that the extraor- 

 dinary development and diversity of the angio- 

 sperms is, in a very large measure, the result of their 

 adaptations to cross-pollination through insect 

 agency. Cross-pollination is known to be distinctly 

 advantageous in many cases. The seeds of cross- 

 pollinated flowers have been shown by Darwin and 

 other investigators to be more numerous and better 

 developed, and the resulting seedlings distinctly 

 larger and more vigorous, than those derived from 

 seeds from self-pollinated flowers. Moreover, a 

 good many flowers, e.g., many orchids, have been 

 found to be quite sterile with their own pollen, 

 which may even act injuriously upon the pistil. It 

 is also a legitimate assumption that the increased 

 variability due to cross-pollination is an advantage, 

 as tending to cause new characters to appear which 

 may be taken advantage of by natural selection. 



The lower types of flowers, such as those of 



