234 



Dr. B. Lewis. On the 



[June 19, 



, and character of growth induced. The percentage and acreage 

 amounts of phosphoric acid also vary very strikingly ; and so again it 

 is with other mineral constituents, but in a less marked degree. 



It will be seen that in the history of so many of what may be called 

 natural rotations, we can hardy fail to learn much that is of interest, 

 not only in reference to the growth of the mixed herbage of perma- 

 nent grass land, but also something of the relative positions of the 

 different plants that are grown separately, in alternation with one 

 another, in the artificial rotations adopted on arable land. 



The botanical results are, moreover, of much independent interest, 

 both by the facts which they already contribute, and by the incentive 

 and direction they may give to future research. 



Lastly, the chemistry of the subject will be found to offer many 

 points of interest, in regard to the variation in the percentage com- 

 position of the produce, according to the manure applied ; to the 

 description of plants developed, and to the character of their develop- 

 ment ; to the availableness of the constituents artificially supplied ; 

 and to the amount and limit of the natural resources of the soil, both 

 actually and compared with the results obtained when individual 

 species are grown in arable culture. 



It will be readily understood that the record, and the discussion, of 

 the agricultural, the botanical, and the chemical history of about 20 

 plots, in 20 different seasons, must involve much detail ; and although 

 it is obvious that facts speoial to any one of the three main divisions 

 of the subject may require for their elucidation reference to those of 

 one or both of the others, it is still believed that it will conduce to 

 clearness, and reduce unavoidable repetition, to maintain the divisions 

 proposed as far as possible. 



On the present occasion, Part I only, entitled — "The Agricultural 

 Results," is presented. In Part II, "The Botanical Results," which 

 will next follow, Dr. M. T. Masters, F.R.S., is joint author. 



XXIV. " On the Comparative Structure of the Cortex Cerebri." 

 By Bevan Lewis, L.R.C.P. Lond., Assistant Medical Officer, 

 West Riding Asylum, Wakefield. Communicated by Dr. 

 Ferrier, F.R.S., Professor of Forensic Medicine, King's 

 College, London. Received June 18, 1879. 



(Abstract.) 



The object held in view throughout this investigation has been that 

 of instituting an inquiry into the minute structure of the cortex of 

 the brain in a prominent member of the Artiodactyla, and to 

 critically compare the results with those obtained from an examination 



