272: ' Retrospective Criticism, 



remarked, that the blackbird seldom attempts commencing music when the 

 temperature is below 42°. The lark will sing, if the sky is serene, at 

 a temperature of 34°. 



In consequence of the long protracted winter frosts, vegetation had 

 been stationary throughout the winter months. The Christmas rose (Hel- 

 leborus niger) had its_flowers formed in December, but did not open tiH the 

 14th of February; snowdrops and the winter aconite were in flower on 

 the 15th, and spring crocuses began to appear above ground. The tem- 

 perature of the last 10 days of February being 37°, vegetation became 

 again stationary. The aurora borealis was brilliant on the evenings of the 

 2d and. 7th, indicative of the unsettled state of the atmosphere which 

 prevailed till the middle of the month. The crocus was in flower on the 

 4th, five days earlier than last season. The mezereon was in flower by the 

 8th. Wheat from Tangier sown on the 22d of January, appeared above 



f round on the 10th, a period of 47 days; mean temperature of that period 

 8*5°, corresponding exactly with privet wheat sown on the 26th of January 

 last year (Vol. III. p. 296.), both as to temperature and period of duration 

 under ground. The iSaxifraga oppositifolia opened its flowers on the 14th, 

 exactly on the same day as last year. Garden peas sown on the 21st of 

 February appeared above ground on the 22d of March, a period of 29 days;, 

 mean temperature of that period, 41°. Apricots were in full blow on 

 south walls on the 22d; the Erythronium Dens Canis, and iVarcissus 

 minor, on the 26th. Gooseberries were in leaf on the 27th ; and the Pul- 

 monaria paniculata was then in flower. The progress of vegetation at this 

 period, it will be perceived, is as near as can be to the corresponding period 

 last season. The only observable anomalies are, the larch trees appear 

 about as forward in leaf as on the 8th of April last season, which may be 

 accounted for by the excessive moisture of the soil throughout the early 

 part of March, and consequent cold produced at the earth's surface by 

 evaporation, affecting the progress of herbaceous plants, while lofty trees 

 enjoyed a higher temperature. The Draba «izoides in the same situation 

 as last year, has not kept pace with its fellows; it having flowered last 

 year on the 16th and this season on the 26th of March. It is not so easy 

 to account satisfactorily for this anomaly. — A. G. April 2. 1831. 



Art. VI. Retrospective Criticism, 



Periodical Publications. — Sir, Accidentally looking over a very well- 

 written article on Strutt's Sylva Britdnnica, in your last Volume (p. 549.), my 

 eye was caught by the following passage : — " We could wish, for his own 

 sake, that Mr.Swainson would not levy so exorbitant a tax on his subscribers 

 as to charge them half-a-crown for about eight pages of titlepage, preface, 

 indexes," &c. Now this, abstractly, is a just animadversion; but, with 

 reference to the work itself, it is a very partial mode of reasoning, and 

 therefore not fair. In each regular number of the Zoological Illustrations 

 (which amount to twelve in thirteen), there are five highly finished plates 

 for 45. 6c?. Now let the writer compare this price with that of three other 

 zoological periodicals, of the same size, and executed with equal care : he 

 will find that in one of these there are six plates for six shillings ; in another, 

 four plates for four and sixpence; and in another, where the letter-press is 

 more copious, two, or sometimes one plate, for three and sixpence. Let 

 me ask the writer, which he would rather have done : the number of plates 

 reduced from five to four, so as to bring the work upon a level with those 

 just alluded to ; or would he rather continue to pay this " exorbitant tax " 

 of half a crown for every thu-teenth number ? It is surely enough that there 

 are still men of science who will devote their time, and moreover their for- 



