18 MICHIGAN BIRD LIFE. 



outermost primary and mimber nine or ten, as the case may be, that primary 

 which is followed directly by the first secondary. When the statement is 

 encountered "second or third primary longest" it must be understood that 

 the actual length of the entire primary is not meant, but merely that in the 

 folded or partly opened wing the tip of the second or third primary extends 

 beyond the tips of any of the others. 



It is not practicable in this place to anticipate and explain all the difficulties 

 which the beginner will experience in attempting to use the artificial keys, 

 but enough has been said to enable him to make a beginning, and with 

 constant reference to the figures and glossary, and especially with the exercise 

 of good sense and fair judgment one should learn very quickly to use these 

 keys successfully. At the risk of being tedious, it should be repeated once 

 more that no measurement should ever be guessed at; the compasses and a 

 measuring rule should invariably be at hand and only in the most obvious 

 cases should their use be omitted. 



AN EXAMPLE OF THE USE OF THE KEYS. 



Suppose we have in hand a freshly killed specimen of one of our small fresh- 

 water ducks. Starting with the Artificial Key to the Larger Groups (page 33) 

 we find the first line, prefaced by a single capital A, to read, ''Distinctly 

 web-footed. — B, BB, BBB." Examination of the bird's foot shows that it 

 is a typical swimming foot, the three front toes being connected with mem- 

 brane or web. If in any doubt we should look for the alternative under the 

 heading AA, which appears farther down the page and is found at a glance 

 because it begins at exactly the same distance from the margin as the line A. 

 But AA reads, "Imperfectly or not at all web-footed," which evidently 

 does not answer for our bird. So we come back to line A and consider the 

 references following it, B, BB, BBB. The three lines beginning with B all 

 relate to the hind toe, and as our bird has a hind toe which is not connected 

 with the front toes by a web it evidently agrees with BB. This in turn is 

 followed by the references E and EE, and on reading the lines so headed 

 and examining our specimen we find the condition described under E, namely 

 the "cutting edges of the bill with comb-like ridges." The reference follow- 

 ing this line takes us to the Order Anseres, Ducks, Geese and Swans, where 

 another key awaits us. 



The short neck, dark color and small size debar our specimen from the 

 group of swans, and its comparatively short legs and long toes exclude it 

 from the geese and confirm our belief that it belongs with the ducks. 



The key to the species of ducks looks somewhat formidable, but it should 

 be remembered that we need only consider one or two points at a time. The 

 short, broad bill, with its strainer-like plates sends us at once to AA, and then 

 to decide between C and CC. Here a little investigation may be necessary, 

 but a glance at the cut of the Ruddy Duck will show that it is quite unlike 

 our specimen and we select CC as the right path. In order to determine 

 now whether D or DD is applicable to the case in point the student should 

 compare figures 15 and 21 and then carefully examine the hind toe of the 

 specimen. The result points clearly to D and places this bird among the 

 "River and Pond Ducks," with the references E and EE to be considered. 

 Although evidently not a very large duck, it is not safe to assume that it 

 belongs under E without actual measurement. With a pair of compasses 

 the exact distance from the front edge of the shoulder (in the closed wing) 

 to the tip of the longest primary must be determined, and since this proves 



