LABOIiATORY STUDIES OF TUB FRUIT 145 



Cranberry. Cross section, showing cavities and attacliuiont of seeds 

 (x 2). The terndiial depression sliowing remains ot tlie lluvvers 

 ( X 10). Soft, fleshy fruits of this sort are termed herriea. 



Checkerberry. — Dissect the fruit. What is the morphological 

 nature of tlie lower, fleshy part? 



Draw a longitudinal section to show all parts — including tlie seeds 

 ill one of the cavities — and their anangeuient (x -3). 



The Rose hip. — Examine the fruit to discover, if possible, where 

 the floral parts were situated. Cut the hip open. Are seeds seen V 

 Are seeds ot Angiosperms produced in an open receptacle or cavity, av 

 these seedlike bodies are? Are they seeds or fruits? The liollow, 

 pulpy portion bearing them on its inner surface is an enlarged 

 reeeptacle. 



Draw a diagram representing a longitudinal section (x 2~5). 



ExEKCiSE XXXVl. Thk Seei> 



The student is already familiar with the interior of the seed — with 

 embryo and albumen. The integuments need to be looked at more 

 particularly than has been done heretofore. 



Squash. — Notice the place at which the seed was broken from its 

 conuectitm with the placenta. It is called the liilurn. Beside tins there 

 is a distinct aperture leading into the interior, the inirropi/le. Cut 

 ciway tlie shell. How many seed coats? This is the characteristic 

 number. The outer is the testa; the inner, the legmen. 



Draw a cross section of the Squash seed (diagrammatic). 



Castor Bean. — On one side observe a straight, dark line, running 

 three quarters the length of the seed (the raphe). At one end is a 

 very slight elevation, the point at which the coats are organically 

 connected with tire kernel ; this point is the elialaza. At the other 

 end is the liilum, nearly covered by a structure called the caruncle. 



Bean. — At one side of the hilum is the micro^iyle, more easily made 

 out if the material has been properly soaked. On the other side of 

 the liiluui, running to the end of the bean, is a ridge, more or less 

 indistinct — the raphe. Overlying its inner exti'emity, next the hilum, 

 is a heart-shaped, purple excrescence, called the slroplnole. 



Di-aw the bean, showing the features indicated ( x 3). 



Outgrowths of the testa. — By the aid ot the hand lens make 

 enlarged drawings of the seeds of IMilkweed and of the Trum]iet 

 Creeper. Cut the seed of tlie Cotton Plant in half. Draw the 

 section, so as to show the length ot the Cotton fibers relatively to the 

 diameter of the seed proper. What is the use of these outgrowths ? 



E.XEitciSE XXXVII. The Fkuit in Relation to Dissemination 



The need of dissemination will be most keenly i-ealized by a rough 

 computation ot the number of seeds produced by a single plant, all 



BUT. OF EOT. — 10 



