69 



This is the case, for example, at Luccombe Chine, where the 

 stems of Dicotyledons, of typical structure, occur in the same beds 

 which yielded Benneitites Gibsonianus. The Secondary Cyca- 

 dophyta show us what this Cycad type of organisation was 

 capable of, in its best days, so far in advance of anything which 

 its modern representatives have to show. They may even give 

 us the clue to what Darwin called the " abominable mystery" of 

 the origin of the true Flowering Plants, though they may not 

 have been on the direct line of their descent. 



Note. — In replying to a vote of thanks proposed by Sir 

 Daniel Morris, and seconded by Mr. Rankin, Dr. Scott deplored 

 the inertia of English investigators and gave instances of fruitful 

 investigations on British Mesozoic material by foreign scientists. 

 The recent elucidation of the structure of the Jurassic Cycads of the 

 Yorkshire deposits, including several new species of Williams onia, 

 had been largely the work of his Swedish friend, Professor 

 Nathorst. He was glad to say, however, that English 

 palseobotanists were now waking up to the value of the fossil 

 treasures of their own country. 



Natural Colour Photography. 



A BRIEF HISTORIC SURVEY. 



By K. Y. Banks. 



Read before the Photographic and Record Section, February 10th, 1915. 



TN discussing colour in photography we must first enquire into 

 the origin or source of colour. Although colour is presented 

 to our vision in a variety of ways the main source of all colour is 

 light. It may seem absurd to say that without light there is no 

 colour, but this very' obvious statement might mean more than one 

 thing. It may mean that from want of light we are unable to see 

 the colours that are there, or it may mean that there are no colours 

 there and that the colour is contained in the light itself. Accepting 

 the latter theory we must assume that say red brick 

 orj green grass are not either red or green in them- 

 selves, but that they have some inherent quality of 

 analyzing the colours of which white light is composed, 

 absorbing some and transmitting or reflecting others. This may 

 be simply described as selective absorption. It involves the pre- 

 sence of a pigment and for that reason may in connection with 

 coloured photography be described as a pigmenting process. We 

 shall find as we proceed with our review that this is the only way 

 of producing coloured pictures that has up to now been brought 

 to a successful issue and acquired a practical use. There are, how- 

 ever, other ways by Avhich colour is presented to our vision and by 

 which coloured pictures have been produced. One of these is by 



