180 



DISCOVERY 



season, the Great Scot will produce a good crop, free 

 from any sign of warts, while the Arran Chief may 

 only show warts and not a sound tuber. In the same 

 way the King George will be free and the British 

 Queen attacked. 



So important and so certain is the immunity that 

 the administration of this disease by the Agricultural 

 Boards in the British Isles is based on the fact, and 

 where the disease is present only immune varieties of 

 potatoes may be planted. Raisers of potatoes are there- 

 fore exerting every effort to produce such resistant 

 varieties having the good cropping and other qualities 

 of those in commerce at the present time, and 

 considerable success is being achieved. If a potato 

 immune both from Wart Disease and ordinary potato 

 disease or Blight (Phytophthora) could be raised with 

 the cropping qualities of some of the ordinary com- 

 mercial potatoes such as Up-to-date and King Edward, 

 the food-supply of potatoes in the British Isles would 

 be increased by at least 20 per cent. This ideal is not 

 beyond the bounds of possibility, as, although no potato 

 is immune from Blight, several — for example Flourball, 

 Champion, and Templar — are immune from Wart 

 Disease and largely resistant to Bhght. They have 

 disadvantages which militate against their general and 

 commercial use, but breeders hope to get rid of these, 

 while still maintaining their resistance to disease. 



The literature on Immunity in Plants is very scanty, and no 

 book is published on the subject. A recent general account 

 is that by Dr. Butler in the Proceedings of Second Meeting of 

 Mycological Workers in India, 1919. Reference may also be 

 made to a paper by Otto Appel in Science lor May 28, 1915. 

 As regards Wart Disease, a full bibliography is given in the 

 author's paper in the Journal of the Royal Horticultural Society, 

 June 1920. 



The Revival of Learning 

 and the Capture of Con- 

 stantinople 



By R. B. Mowat, M.A. 



Fellow and Assistant Tutor 0/ Corpm Clirisli College, Ox/ord. 



The Revival of Learning is the most momentous fact 

 in the history of Europe. With the decline and fall 

 of the Roman Empire in the fifth century a.d., a great 

 part of the literature and learning of the ancient world 

 disappeared for centuries. The " Dark Ages " en- 

 sued, when life was very insecure, and education, 

 except within the walls of certain fortunate monasteries, 

 scarcely existed. The " Feudal System," according to 



which every man had a fixed place in the community, 

 under a master, saved society in the Middle Ages, but 

 at the expense of all political, social, or intellectual 

 freedom. 



The Middle Ages may be considered to begin, and 

 the Dark Ages to have ended, with the coronation of 

 Charlemagne as Emperor at Rome in a.d. 800. From 

 Charlemagne's time onward, the role of the Church 

 in moulding the manners ajid minds of men becomes 

 more and more effectual, so much so that the eleventh 

 and twelfth centuries have been called " the Ages of 

 Faith." It was indeed faith, rather than reason, that 

 ruled in the Middle Ages ; and although the services 

 of men hke St. Anselm or St. Thomas Aquinas to the 

 human intellect must always be recognised, it still 

 remains true to say that the Middle Ages were marked 

 by a certain rigidity ; every man was definitely fixed 

 in his class, in his profession, in his corporation ; the 

 use of the human reason was strictly limited, and 

 investigation and argument were conducted according 

 to fixed rules. One of the greatest and most open- 

 minded of the Media^valists asserted that the human 

 intellect was not meant to be able to discover every- 

 thing ; for if it had been able to do so, there would 

 have been no scope for the life of Christ in the world : 



State contenti, umana gente, al quia ; 

 Chd, se potuto aveste veder tutto, 

 Mestier non era partorir Maria. 



(Dante, Purg., iii. 37.) 



Seek not the wherefore, race of human kind ; 

 Could ye have seen the whole, no need had been 

 For Mary to bring forth. 



During this long mediaeval period, this time of 

 intellectual rigidity, the greater part of classical 

 literature was not studied ; indeed, manj' of the 

 classics which we now have were not at that time 

 known to exist at all — such as Cicero's Letters toAtticus, 

 of which the manuscript was not discovered till 1345- 

 The great secular book of the Middle Ages was Virgil's 

 JEneid. Comparetti, in his work Vergil in the Middle 

 Ages (Virgilio nel medio evo), has sho\\Ti how this poet 

 was regarded as a prophet, a grammarian, a wizard, 

 and as a imiversal compendimn of learning. 



Thus the learning of the Middle Ages was chiefly 

 derived from Latin worfts, and from only a restricted 

 number of Latin works. Something was known of 

 Greek literature, but only tlirough translations — 

 some of Aristotle's works, for instance, were known 

 through Arabic translations, which in turn were 

 rendered into Latin. It was not merely, however, 

 that Hellenic literature had disappeared ; the Hellenic 

 spirit, the spirit of freedom and inquiry, had also been 

 forgotten. The Middle Ages ended when classical 



