THE CLASSIFICATION OF ANIMALS iii 



each. This example or lesson in classification can be given just as 

 well of course with other species of birds, or with a set of some other 

 kinds of animals, if the teacher prefers. Insects. are especially avail- 

 able, butterflies perhaps offering the most readily appreciatfcd resem- 

 blances and differences. 



Species. — Examine specimens of two male downy wood- 

 peckers (the males have a scarlet band on the back of the 

 head). (In the western States use Gardiner's downy 

 woodpecker.) Note that the two birds are of the same size, 

 have the same colors and markings, and are in all respects 

 alike. They are of the same kind; simply two individuals 

 of the same kind of animal. There are hosts of other 

 individuals of this kind of bird, all alike. This one kind 

 of animal is called a species. The species is the smallest* 

 group recognized among animals. No attempt is made to 

 distinguish among the different individuals of one kind or 

 species of animal as we do in our own case. 



Examine a specimen of the female downy woodpecker. 

 It is like the male except that it does not have the scarlet 

 neck-band. But despite this difference we know that it 

 belongs to the same species as the male downy because 

 they mate together and produce yoimg woodpeckers, male 

 and female, like themselves. There are thus two sorts of 

 individuals,"!- male and female, comprised in each species 

 of animal. A species is a group of animals comprising simi- 

 lar individuals which produce new individuals of the same 

 kind usually after the mating together of individuals of two 

 sexes which may differ somewhat in appearance and structure. 



Examine a male hairy woodpecker and a female; (in 

 western States substitute a Harris's hairy woodpecker). 

 Note the similarity in markings and structure to the downy. 

 Note the marked difference in size. Make notes' of meas- 



*The lesser group called variety, or subspecies, we may leave out of 

 consideration for the present. 



fSome species of animals are not represented by male individuals; and 

 in some all the individuals are hermaphrodites. 



