42 SCUTELLARIA WRIGHTIL WRIGHTS SKULLCAP. 



tissues, and cannot escape unless it is pressed out. This explains 

 why we rarely smell an orange without handling it, or without 

 its having been handled, while the odor from a bed of mint is 

 wafted to us on every breeze. 



We have said above that not all Labiata:' have labiate corollas, 

 and that not all flowers with labiate corollas are Labiato'. It is 

 not always possible, therefore, to distinguish the order at first 

 sight by the shape of the flowers, and there are genera among 

 the VcrbenacecF, the Boragiiiacccr, and the Scrophulariacccr, which 

 might easily be mistaken for Labiates. But however closely the 

 floral structure may resemble the Labiates, there are always cer- 

 tain other indications which will lead the student in the rio^ht 

 direction. Thus square stems never occur among the Boragijia- 

 cciT, while they are one of the leading characteristics of the 

 Labiatcr. Among the Vcrbenaccar there are some species \\'ith 

 square stems, but the ovary is single, while in the Labiato' it is 

 invariably deeply four-lobed. In ScrophulariacecE, finally, the 

 ovary is a two-celled pod, with the pistil proceeding from its 

 apex, while in Labiat<^ the pistil rises up between the four lobes 

 of the ovary, and distinctly from their base. There are many 

 other points of difference between the four orders named, but 

 those we have just alluded to are the leading ones, and will be 

 sufficient to enable the student to decide in doubtful cases. 



Of the genus Scutellaria, to which our species belongs, Dr. 

 Bromfield remarks, in his " Flora Vectensis," that " in the struc- 

 ture of the flowers, and in general habit, this genus betrays the 

 strong affinity of the natural orders Labiato' and Scrophulariaceo'r 

 In the last-named order, the embryo in the seed, as seen under 

 the microscope, is always more or less curved, while in Labiatce 

 it is straight, with very few exceptions. Scutellaria is one of 

 these exceptions, and hence the affinity with Scrophulariacecs is 

 apparent also in this feature. 



Of all the genera belonging to the order, Scutellaria is one of 

 the most important, as it embraces about one hundred and fifty 

 species. It seems to have its home-centre in the United States, 



