CUCURBITA 587 



the base of the neck of the nucellus. It then develops branches 

 which traverse the nucellus and the inner integument, also main- 

 taining an intimate connection with the internal layers of the 

 outer integument. This behavior of the pollen tube has a func- 

 tional significance, according to Longo, since the branches of the 

 tube act as haustoria in the translocation of nutritive material. 



The Fruit. — The fruit of the cucurbits is one of the largest 

 found in the plant kingdom. It is indehiscent with the fleshy 

 receptacle adnate to the pericarp, and is classified as an inferior 

 berry or pepo. The varieties of squash and pumpkin are numerous. 



Fig. 307. The fruit of Hubbard Squash. (Courtesy Bur. Plant Industry.) 



and the list is constantly increasing owing to hybridization and 

 experimental breeding, so that there are wide variations in fruit 

 characters, especially with respect to shape, size, texture of the 

 skin, and color. Varieties of C. Pepo have fruits some of which 

 are round, flat, and scalloped at the edges, or elongated and crook- 

 necked; while others are short and club-shaped, or acorn-shaped 

 and variously grooved. Varieties of C. maxima include the 

 Hubbard squash which is roughly elliptical, tapering to a curved 

 stem end, and others that are turban-shaped owing to the fact 

 that the fleshy receptacle and the ovary are diverged for a longer 

 distance than is usually the case. (Fig. 307.) Those of the banana 

 type are elongated and somewhat pointed at the ends. In C. 

 moschata the fruits are also variable in shape, some having long 

 curved necks while others are more oval or spherical. The surface 

 may be smooth, warty, or covered with spines and other types of 



