^. 



Botany and Zoology. 439 



mastication of the leaves and bark while we write yields not the slJglitest 

 trace of acridity and hardly any of astringency; no more, certainly, than 

 a Beech-leaf. We never heard of the seeds being eaten ; and as they 

 are "about the size of a grain of barley," or not much Jarger, and In 



. a thick bony coat, they are not likely to become an important article 



of diet. After some search, w^e find the sonrce of these extraordinary- 

 statements in the Medical Flora of the excentric Rafinesque. He says 

 the seeds are cilled Pistachio nuts in the Southern States, are rather oily 

 and palatable, &c., but he neglects to mention their size. He adds, " the 

 bark and leaves are somewhat bitter, very astringent, leaving a sweetish 

 pungent tHste, The smell is not unpleasant. It has not been analyzed 

 as yet, but probably contains tannin, amarine, extractive, and an essential 

 oil." To all this, Endlicher, on the strength of "the sweetish pungent 

 taste/' has added the acridity; and so one of the blandest and most use- 

 less of shrubs gets a world-wide and wholly factitious reputation for active 

 medical qualities and esculent seeds; and even Dr. Griffith, who must 

 have known the shrub, has been induced to give it a place in his Medical 

 Botany. 



Our remaining remark relates to the random way in which mere anal- 

 ogies are mixed up with affinities in estimating or expressing tlie relation- ^ 

 ship of orders, ifcc, in this as in some other more notable works. It is^ 

 or at least ought to be, well understood, that mere analogy, i, e., likeness 

 in some one respect only, however striking the imitation, is no indication 

 of relationship, but that relationship rests upon affinity^ i. e., upon agree- 

 I ment or similarity in the whole plan of structure, and especially of tloral 



j structure, whether general or particular, as the case may be. To speak, 



therefore, of 'evident' and 'most distinct' affinities between Coniferce and 

 Lycopodiacece is an example of this prevalent misconception of what affinity 

 is. This is more intelligible, however, than the 'approach' suggested of 

 Aquifoliacece to Loganiaceoe and Apocynacece, while their resemblance to 

 Celastracece is thought to be of small account; or that o? Umbelliferce to 

 Rabiacers^ SaxifmgacecBj and even to Geranlaceos^ to which the resem- 

 blances do indeed "seem rather superficial." AgiuHy Xanthoxylacece (i. e. 

 Hutacece) are said to have considerable affinity to Oleacem^ because Pielca^ 

 in the former, has a samaroid fruit, as has Fraxinus in the latter. May 

 we add, as quite as much to the purpose, that the common Xanthoxy- 

 lums have pinnate leaves, and are popularly called Prickly Ash ? 



The study of affinities is neither guess-work nor divination, but a mat- 

 ter of logical deduction from structure, based upon scientific principles, 

 principles recognized and acted upon by sound botanists with considerable 

 unanimity, although they have never been reduced to a system, nor ex- 

 pounded in detail, so as to make them matters of elementary instruction. 

 Until this desideratum is supplied, the young botanist can do no better 

 than to take as models the writings of Brown, and of th(^e botanists 

 who, according to their ability, have most closely followed the footsteps 

 of this master in science. 



Having continued this review far beyond our intention at the outset, we 

 have small space left for noticing the best part of Prof. Ilenfrey's treatise, 

 namely, the third or Physiological part. Suffice it to say that, in the im- 

 portant chapter on the physiological anatomy of plants, our author writes 



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