Sentence:  A little work on bees which I read some time ago, states that bees collect pollen only on flowers of the same species, in order not to mix the pollen of different flowers together, and I have several times observed this statement as perfectly true during the time when <WSD>resedas</WSD>, roses, and geraniums adorned a bed close to a bee-hive. The same bee or humble-bee which had been on a <WSD>reseda</WSD> would only visit <WSD>resedas</WSD>, another only geraniums, &c. 
Meaning of the word marked with <WSD> tags:  Any of various plants of the genus "Reseda" having small, pale grayish green flowers, such as dyer's rocket ("Reseda luteola") and mignonette ("Reseda odorata").