February 24, 192 1] 



NATURE 



825 



histogenetic or experimental, and in this direction 

 also the book fails of justification. 



Cancer research, in addition to its occupation 

 with the empirical treatment of the disease, is 

 • concerned with the answer to two questions. In 

 what way do cancer cells differ from cells of the 

 same kind which are not cancerous? What are 

 the changes by which ordinary cells become can- 

 cerous? At present our knowledge only suffices 

 to give the most general and superficial answer to 

 the first question, and to the second no answer as 

 yet can be given. In the unvarying parenchymata 

 of transplantable tumours we possess an ideal 

 material for investigating the first of these prob- 

 lems and for testing hypotheses framed to solve 

 it. The advances which are even now being 

 made in the experimental production of cancer 

 are providing the means for a rational attack on 

 the second. The time has come when specula- 

 tion and hypothesis must take their proper place 

 as servants in the investigation of cancer, not 

 substitutes for observation, experiment, and 

 proof. J. A. Murray. 



Virgil's Botany. 



Tfee Trees, Shrubs, and Plants of Virgil. By 

 John Sargeaunt. Pp. vii-)-i49. (Oxford: B. H. 

 Blackwell, 1920.) Price 65. net. 



THERE are many lovers of Virgil who are 

 neither scholars nor botanists, and their 

 number seems to be increasing, just lovers of 

 his poetry, who are content without any great 

 knowledge of grammatical criticism — content 

 with translating quercus and robur by the same 

 word "oak," for whom taeda, picea, pinus, abies 

 are equally "fir" or "pine," though they would, 

 for the most part, hesitate to affirm on the 

 authority of Gallus that "Violets are black and 

 blaeberries {vaccinia) too." To all such the book 

 now before us, written by a former master at 

 Westminster, who grows Virgilian plants in his 

 English garden, and has travelled in Italy, comes 

 with the promise of help. We hope with its aid 

 to attain to a better understanding and, therefore, 

 to a truer appreciation of the poems, especially 

 of the "Eclogues" and "Georgics," the country 

 poems. And at first we are not disappointed. 



It is true that we have to get over the initial 

 difficulty of the title ; for are not trees and shrubs 

 plants too? Why not say "herbs"? It is as 

 though we were to write of men and animals. 

 Letting that pass, however, we find a very in- 

 teresting introductory chapter, which deals with 

 the geography and the distribution of plants in 

 the valley of the Po two thousand years ago : 

 NO. 2678, VOL. 106] 



what enormous changes, natural and artificial, 

 have been wrought in the intervening years, turn- 

 ing Gallia Cisalpina of Virgil's day into Lom- 

 bardy of our own ! — the wolf no longer descends 

 from the dense forests of the Apennines to ravage 

 the flocks ; the olive now flourishes on the shores 

 of Benacus. Then we come to a very interesting 

 discussion of the colours mentioned by Virgil— 

 purpureus and ferrugineus, niger and ater, can- 

 didus and albus, flavus, luteus and julvus ; the 

 particularly elusive caeruleus is, however, not 

 mentioned, and it is a pity that when fields of ripe 

 corn, yellow sands, auburn hair, gold are given 

 as examples of objects to which the colour jiavus 

 is attributed, flava oliva is not given too. The 

 subject of these colour names is a very obscure 

 one. We know very little about it, and that " in 

 some contexts white means little more than not 

 black and black little more than not white " i5 

 wisely said. Might not the saying be further 

 extended? Do not we, on the other hand, very 

 often insist too minutely on the differentiation and 

 discrimination of natural colours and of colour 

 names? People have been known to fall out and 

 almost to quarrel over the colour of autumn 

 saffron, Colchicutn autumnale : is it pink or is it 

 mauve? What is mauve? 



But when we pass from the introduction to the 

 body of the book we are disappointed : it is full 

 of solid and valuable information, but the many 

 inaccuracies, some of which are so obvious that a 

 very slightly informed reader can scarcely fail to 

 detect them, rob it of a great part of its value 

 and inspire a strong mistrust of even the better 

 part. 



P. 66. The true laurel is the bay (Laurus 

 nobilis), from which we get camphor and 

 cinnamon. 



P. 97. The capsules [of Papaver somniferum] 

 abound in opium or hashish. 



Less obvious at a first reading are the wrong 

 attribution of Acanthus to the Scrophularineae 

 (not Scrofularineae) ; the statement (p. 37) that the 

 purple crocuses of our gardens are Crocus versi- 

 color, whereas they are C. vernus ; and the con- 

 fusion (p. 137) between Viscum, our mistletoe, 

 and Loranthus, which, accordinjf to Arcangeli, 

 grows on oaks and chestnuts. 



What can be the meaning (p. 91) of: "The 

 victors in the games are crowned with olive 

 blossoms, which drop upon their yellow pollen " 

 (" JE.'^ V. 309)? The line in the original is: 

 . . . flavaque caput nectentur oliva. And why 

 should the foliage of both the olive and the ole- 

 aster be called " heavy "? Is this a misprint for 

 " hoary "? 



