KINDS OF PARENTS 67 



derived from Hermes and Aphrodite, Greek male and 

 female gods. 



Many of the lower plants, and some of the simpler 

 animals produce both kinds of gametes in the same 

 individual. In such a plant as Vaucheria, or Oedogonium, 

 or some of the moss plants, both kinds of gametes are 

 produced near together on the same plant. 



In the fresh-water hydra, described in Chapter Four as 

 reproducing by buds, reproduction by gametes also occurs. 

 In this little animal eggs and sperms are formed at 

 somewhat different parts of the body, and each hydra is, 

 so to speak, one sex at one point and the other sex at 

 another point. 



This state of having both sexes in one organism is 

 known as hermaphroditism. In addition to the instances 

 mentioned above, it occurs regularly in many of the 

 worms, in snails, oysters, etc. Hermaphroditism may 

 occur in occasional individuals of higher species, even 

 among the vertebrates. 



3. The Organs That Produce Eggs and Sperms. 



Although a plant or an animal may produce both male 

 and female offspring at the same time, it is usually true 

 that such a parent has special and different organs for 

 each. Often they are definitely located at different parts 

 of the body. 



The organs that produce the gametes are quite differently 

 named in different organisms. Generally among animals 

 the male organ, which produces sperms, is known as a 

 spermary or testis, and female organ is called an ovary. 

 Among plants the organ that produces sperms is called 

 an antheridium. The female organ in which the egg is 

 produced is called, in different groups, oogonium or 

 archegonium. 



Where gametes are alike, there is only one kind of 

 organ to produce them. There is no reason why there 

 should be more. When the gametes become different, 



