286 NATURAL SCIENCE. -Oct., 



pletely closed by the calyx-teeth. In rain the pedicels bend outwards 

 tintil the axes of the calyces are nearly horizontal. At the same time 

 the calyx-teeth bend out so that the mouth is open. 



I. Ziziphora capitaia (Linn.), Figs. 1-4. 



A herbaceous annual, with erect stem. The flowers are borne 

 in verticillasters, forming a dense terminal head. When in fruit, the 

 four leaves immediately beneath the head are folded up round it, so 

 as almost to enclose it. The calyces are almost erect, and the mouth 

 quite closed by the teeth. The calyx is tubular, elongated, hairy 

 outside, glabrous within, except for a thick ring of hairs at the throat. 

 Rain or moisture cause a rapid movement to take place. The leaves 

 folded up round the head bend out rapidly ; the calyces bend 

 outwards, so that they become more horizontal, and the calyx-teeth 

 open. By sharply shaking the plant the nuts are thrown out to 

 some distance. 



EXPLANATION OF FIGURES. 



Fig. I. Ziziphora capitata ; a capitulum in fruit; in the dry condition 

 X It c-'^^) 



Fig. 2. The same; wet condition. 



Fig. 3. Calyx of Z. capitata ; dry condition. 



Fig. 4. The same ; wet condition. 



Fig. 5. Ziziphora tenuior, a spike in fruit ; dry condition. (X i.) 



Fig. 6. The same ; wet condition. 



Fig. 7. A small portion of the spike of Z. tenuior, most of the leaves and calyces 

 having been removed ; dry condition. 



Fig. 8. The same ; wet condition. 



Fig. g. The mouth of the calyx of Z. tenuior in the dry condition ; longitudinal 

 section, showing the ring of hairs in the throat and the teeth closed. 



Fig. id. The same ; wet condition. 



Fig. II. Lallemantia peltata; a node of the spike, all the calyces and bracts 

 having been removed except two ; dry condition. (xi|.) 

 Fig. 12. The same; wet condition. 



Fig. 13. Mouth of the calyx of L. peltata, seen from the front ; dry condition, 

 the teeth closing the opening. 



Fig. 14. The same ; wet condition ; the teeth having moved slightly apart. 

 Fig. 15. Ocimum canipcchianum (?) ; part of the spike in fruit ; dry condition. 

 .(XI^.) 



Fig. 16. The same ; wet condition. 



Fig. 17. A calyx of 0. campechianum ; dry condition ; the others in same whorl 

 having been removed. 



Fig. 18. The same ; wet condition. 



Fig. 19. The same ; longitudinal section, showing the hairs at the throat. 

 Fig. 20. Part of the spike of Salvia gigantea. ( X i.) 

 Fig. 21. A calyx of S. gigantea ; dry condition. 

 Fig. 22. The same ; wet condition. 



Fig. 23. Lamium flexuosiim. A calyx seen from the front, showing the teeth 

 curved across the opening ; dry condition. ( x 5.) 



Fig. 24. The same; the teeth bent apart; wet condition. 



