2IO GENERAL BIOLOGY 



i) Blended inJieritance. The offspring may possess 

 characters intermediate between those of the parents. If 

 one parent be short and the other tall the offspring may all 

 be of intermediate height. 



2) Intensified inJieritance. The offspring may be more 

 extreme than either parent. If one parent be dark and the 

 other light, the offspring may be darker than the dark 

 parent. 



3) Heterogeneous inheritance. The offspring may ex- 

 hibit characters differing in kind from those of either parent. 

 Certain races of white and buff pigeons when bred together 

 give slate colored offspring. Possibly, more knowledge of 

 the characters involved in such cases may show them less 

 lawless than has been thought. 



Alternative inheritance. When parental characters are 

 preserved in the hybrids, unfixed and unaltered, we have 

 alternative inheritance — the type that has hitherto received 

 most attention, and which in its behavior seems to offer the 

 closest parallel to the behavior of the chromosomes. The 

 offspring of the first generation exhibit the characters of 

 one parent or of the other ; but when these hybrids are bred 

 together, in their offspring the characters of both parents 

 reappear. In the first generation hybrids one character 

 appears (is dominant) , and the other disappears (is latent 

 or recessive). Both characters are present, but both cannot 

 appear at the same time ; a flower cannot at the same time 

 be fragrant and scentless. Both have been inherited, how- 

 ever, along with or by means of the duplicate apparatus for 

 conditioning egg development, and in succeeding genera- 

 tions the parental characters will reappear. This type of 

 behavior among hybrids was first studied carefully by 

 Gregor Mendel, and is often called Mendelian inheritance. 



