Disturbances of the visual functions / by W. Lohmann ; translated by Angus Macnab.

  • Lohmann, W.
Date:
1913
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Licence: In copyright

Credit: Disturbances of the visual functions / by W. Lohmann ; translated by Angus Macnab. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    perception of the double retina (in Heeing's sense). In my opinion, it is far more likely that appreciation of solidity is of central origin and due to the variable impression which the bodily form of objects makes on our sensory organs. The world around first crosses the threshold of the awaking- consciousness of a child, when it has learnt to translate all sense- impressions into a plastic form with the consciousness whether they belong or not to individual objects^ {cf. Chapter X.). With regard to the genesis of vision I may finally refer ta Hartmann's saying, quoted by Uhthoff in similar circumstances: ''In mankind the child appears to enter the world with nothing, and must learn all; in truth, however, he has an unbounded wealth compared to the nimble and alert chick creeping from the egg^ he brings it all in undeveloped form, for those germs of development are so many, that only after nine months of foetal life can they be shadowed forth in the embryo. So we have the maturing of character by progressive development of the mammalian brain going hand in hand with learning, i.e., the moulding of that character by use, and thus we finally have a much richer and fuller result than the mere instinct of the animal can show. Colour Sensation in the Child.—Preyer^ states that children do not distinguish blue from green with certainty. He goes on to show that black, white, yellow and red are the first colours to be correctly named; green and blue, later. Probably the results of colour painting do not exactly correspond to a like defect in the power of distinguishing or recognizing colours. W. A. Nagel^ found red-green blindness was quite as readily excluded in his little son as was blue-yellow blindness, although the child had learnt all the colours and kept them in mind throughout the tests, except only blue, which at first he recognized, but would forget in a few days. Warburg's* researches show that there is a definite corre- spondence between the ability to name colours, and the degree of intelligence of the child. The more intelligent the child the less his deficiency in colour nomenclature. The results of a colour test in a child of 6 years, are only to be accepted with distinct reserve, in the absence of an efficient test of intelligence. This uncertainty, which we have just mentioned, in recognizing blue is the more interesting, as tlae defect is met with in the writings and poems of the ancients. Homer's ]3lue-blindness.—The controversy as to whether Homer was blue-blind or not, is due to the English statesman Gladstone, who, on philosophical and archaeological grounds, advanced the view of the blue-blindness of the ancients, in a ^ LoHMANN: Zur Frage nacli der Ontogenese des rauiulichen Sehens, Zeitschn f. Sinnesjjliys., xlii. 2 Die Seele des Kindes, 6 Aufl., 1905, Bd. xlii. ^ Journ. of Conip. Neurol, mid Psych., xvi. ^ Miincli. mecl. WocJienschr., 1909.