EPIDENDRUM VENOSUM.' — VEINED TREE-ORCHIS. 55 



were exposed to the full sunlight, and would be liable to be 

 dried completely a few hours after a shower of rain. It is there- 

 fore only when there is continuous dampness and shade on the 

 branch that the seed can grow; and this is of course best secured 

 in the deep recesses of the forest, or on some peculiar class of 

 trees, which at the germinating season of the year offers the best 

 of these growing conditions. But though shade and gloom be 

 necessary for germinating, the growing plant loves sunlight and 

 a dryer air. The growth therefore is weak, and the flowers few 

 in their usual place of growth; but if a tree, covered with plants, 

 finds itself eventually exposed to full sunlight, the plants assume 

 great vigor, and flower in profusion. We have in these cases 

 a very valuable lesson as to the working of nature. She evi- 

 dently cares far more for the welfare of the race than of the 

 individual, for she makes the individual to grow in places not 

 the most favorable for- individual development, because the 

 race is thus the better preserved. The individual plant there- 

 fore has very little power of selection. It has to do as it must 

 rather than as it likes, and it is a great gain to the student of 

 nature to clearly perceive this law. 



We may regard it as a piece of good fortune that this beautiful 

 species has wandered up through the ages from Mexico to our 

 territory, so that we can include it among the illustrations of the 

 native flowers of the United States. For it will give us a faint 

 idea of the great beauty of tropical forests in which epiphytal 

 orchids are exceedingly numerous, and far excel in gorgeous- 

 ness the species illustrated here. The chief variations generally 

 are in the form and markings of the lip, as what we might style 

 the sixth petal in an orchid flower is called. Most students 

 know that an extensive type of flower is that which has three 

 leaves called sepals in one whorl making the calyx, and then 

 three more making the inside set of petals or the corolla; but 

 even these whorls are formed in a line, spiral though it be. The 

 three divisions in each whorl are not formed together, but one 

 after another, and thus in the whole six there are a first and a 



