342 TRANS. ST. LOUIS ACAD. SCIENCE. 



arrangement in Scutellaria alpina, which he says agrees in this 

 respect with Phlomis Russe.liana. In making a comparative study 

 of several species of Scutdlaria, he finds that this arrangement is 

 most highly perfected in S. alpina, while S. galertculata is inter- 

 mediate between 8. alpina and S. minor. The elastically-hinged 

 arrangement in Phlomis tuberosa is as follows : — That portion 

 of the tube of the corolla which connects it with the upper lip is 

 slightly inflated as shown in Figs, i and 3, while above this in the 

 upper lip, on each side, at its farther end, is a small groove run- 

 ning to a point, and above this swollen portion on the tube of 

 the corolla immediately back of these grooves there is a well pro- 

 nounced keel. This keel enables the upper lip to be moved back 

 at an agle of 45°. The lip remains in this position till the insect 

 leaves the flower, when it again returns to its former place. By 

 this arrangement the flower is protected from unbidden guests, as 

 only such insects are able to get at the nectar as can push the 

 upper lip back. The four stamens are arranged in two sets, and 

 are somewhat shorter than the two-lobed style. The anther cells 

 face the lower lip. The filaments of the shorter pair are attached 

 somewhat above the longer pair on the tube of the corolla, well up 

 to the throat (Fig. 5). The longer pair, attached somewhat lower 

 down on the tube of the corolla, lie above the style (Figs, i, 3,3 & 

 5), and extend somewhat farther out than the lower pair, but the 

 filaments of this longer pair differ from those of the short stamens 

 in having a peculiar arrangement to hold the style in position 

 (Fig. $a'). These filaments end in a pair of awl-shaped append- 

 ages that rest against the opposite side of the tube of the co- 

 rolla, and form a little arch over the style. Experimentally their 

 action can be demonstrated by cutting a flower open with a 

 pair of scissors and applying a needle to the style. The style 

 has free movement in the arch, and when moved, as it must be 

 when the insect enters the flower to get nectar, it easily returns 

 to its position over these appendages. According to Loew (61 d) 

 the appendages in Ph. Russeliana are for the purpose of holding 

 the stamens in position, and he thinks that the hairs in the upj^er 

 lip also serve the same purpose. 



Insects, attracted by the clusters of bright purple flowers, find 

 a landing-place on the lower lip of the corolla, and experience no 

 trouble in finding the nectar, as there is a well marked groove in 



