So THE WOODLANDS. 



circumstances ? Modern investigation has shown 

 that this is accomplished largely by means of the 

 agency of insects. Bees and flies entering certain 

 flowers brush off the pollen and carry it away with 

 them ; they enter other flowers and the pollen is left 

 behind, adhering to the stigma. An entire volume 

 of considerable size, teeming with facts, has been 

 written on this simple subject, especially with re- 

 ference to one order of plants, the Orchids. It is 

 impossible to summarize such a work in a few lines : 

 the conclusion may be thus stated. Insects and 

 other agencies are constantly at work, contributing to 

 the fertilization of plants. 



The orchids are plants which abound in damp 

 tropical forests. The flowers have the most singular 

 of forms, often resembling insects ; and the structure 

 of them is very peculiar, indeed, so much so, that 

 external agencies are essential to achieve their ferti- 

 lization. Some orchids are epiphytal, growing upon 

 trees ; others are terrestrial, growing on the ground. 

 Terrestrial orchids are the only kinds represented in 

 our flora, and of these several species occur in woods. 

 The flowers are very irregular in form, sometimes with 

 a sweet spicy odour, without any true stamens, but 

 the pollen combined in two compact waxy masses, 

 the roots in many cases furnished with a tuber, which 

 is replaced by a new one every year. 



One of the commonest of wood orchids is the Tway- 

 blade, 1 with a pair of leaves, between which rises a 

 spike of small green flowers. Another common 



1 Listera ovaia* 



