78 



FRUITS 



along its dorsal sutures in this way, the segments into 

 which it divides are made up of the' two contiguous halves 

 of adjacent carpels, just as if we should fasten a number 

 of leaves together by their edges and then split them down 

 their midribs, we should get an equal number of sections 

 made up of the adjacent halves of different leaves. And 

 on the supposition that carpels are altered leaves, this is 

 precisely what happens in the case of syncarpous capsules 

 such as we have been examining. 



104. Modes of Dehiscence. — Make a diagram of the 

 mode of dehiscence of your specimen, and compare it with 

 that of a pod or the castor bean, jimson weed, St. John's- 

 wort, flax, etc. ; or if specimens cannot be obtained, with 

 the accompanying diagrams. What difference do you 

 ,5^ j68 perceive in their modes of dehiscence.' 



The first of these is called 





105. Loculicidal (Fig. 167), because it 

 splits through the back of the carpels di- 

 rectly into the cells or loculi, a word mean- 

 ing "little chambers." The second is 



169 170 106. Septicidal, that is, the dehiscence 



167-170.— Diagrams takes place through the septa, or parti- 



of dehiscence {after . i-.i, ,,/-r^ 



Gray): 167, loculi- tions that divide the cells (Fig. 168). 

 cidai; 168, septicidal; Either of these modes may become 



169 and 170, septi- •' 



^'^*^^'" 107. Septifragal, as in the morning- 



glory, where the carpels break away from the division 

 walls, leaving them attached to the axis of the fruit 

 (Figs. 169 and 170). 

 Another common form 

 is the 



108. Circumscissile, 



in which the upper part 

 of the pod comes off like 

 the lid of a dish, as in 

 the purslane, plantain, ''' '7« 



, , ^, ^ 171. 172. — Circumscissilecapsuleof anagallis: 



henbane, amaranth, etc. 171, dosed; 172, open. 



