82 THE AMERICAN BOTANIST 



moisture. The embryo is well supplied with chlorophyll and 

 the endosperm, by which the seed is surrounded, also contains 

 chlorophyll and apparently is able to make additional food for 

 the young plant. The cotyledons are very closely joined to the 

 endosperm and absorb nourishment from it. The Mistletoe 

 seldom fails to deform and often kills the plant upon which 

 it grows, notwithstanding the fact that it is not wholly a para- 

 site and makes some of its food. 



Valuable Pollen. — It may surprise some people to 

 learn that even such an apparently insignificant thing as pollen 

 may be valuable enough to guard from thieves. At a recent 

 orchid show in England, all sorts of precautions were taken to 

 pi event envious orchid hybridists from carrying off the pollen. 

 The present race of cultivated orchids are nearly all the pro- 

 ducts of various crossings. Occasionally an unusual hybrid 

 sells for thousands of dollars. Those who have plants that 

 are likely to bring crosses of this kind are, of course, very 

 careful to see that none of the pollen gets into the hands of 

 competitors. The latter, however, by visiting the exhibits of 

 fine orchids may carr}^ away the precious pollen and make 

 crosses of their own. Some pollen if properly cared for may 

 remain good for six months and be sent half way around the 

 world. Therefore if you have any unique specimens of orchids 

 remove their pollen masses before allowing them to visit the 

 flower show. 



The White Pine Rust. — ^The white pine is threatened 

 with a new disease that, if allowed to spread, v^'ill practically 

 exterminate this invaluable timber tree in America. This dis- 

 ease is the European blister rust {Perideriniuin strohi) which 

 is well-known in Europe but which has but lately appeared in 

 this country. This rust has the peculiar habit of requiring two 

 different kinds of plants upon which to complete its life history. 

 One of these plants is the common currant or gooseberry. 



