l62 



SCIENCE. 



[Vol. XII. No. 296 



withdrawal of light. But, in the present state of our knowledge, we 

 become painfully aware that we are lacking sufficient data to group 

 even our most important forest-trees in a series according to light- 

 requirements. This is not so, however, in Europe. Some forty 

 years ago German foresters made observations along this line, for- 

 mulating them and elaborating rules for the management of the 

 various species, especially in thinning, mixing, and cutting for re- 

 production ; and, although these rules have been practised for so 

 long a time based on empirical knowledge, it is only now that Dr. 

 Kienitz offers a physiological explanation of the difference in the 

 behavior of trees under changing light-conditions. He found that 

 on the same branch those leaves which are developed under the 

 full influence of the sunlight are not only, as was known before, 

 often larger and always tougher in texture, and thicker, but they 

 have a larger number of stomata (or ' breathing-pores '), than those 

 formed under less exposure to sunlight. The same, of course, was 

 observed in individual trees grown under shade and in full enjoy- 

 ment of light. If, then, the trees which have their foliage formed 

 under the shade of outgrowing neighbors are suddenly placed in 

 different light-conditions, the foliage is not adapted to perform its 

 function as energetically as the stronger light necessitates. The 

 buds which are formed in deficient light, show also in their leaves 

 a deficiency in the number of stomata; and in consequence the 

 favorable influence upon wood-formation, due to increased light, 

 for which the thinnings and interlucations are made, become in fact 

 noticeable only the second year, when new buds, developed under 

 the increased light-influence, have formed leaves adapted to the 

 changed conditions. In conifers, which hold their leaves for sev- 

 eral years, this adaptation naturally takes a much longer time ; and 

 under unfavorable conditions, if moved too suddenly from the shade 

 into the light, they often lose their old foliage, and even die before 

 the new foliage adapted to the light-influence is sufficiently devel- 

 oped to sustain the increased demand of respiration, transpiration, 

 and assimilation. 



" The importance of this knowledge becomes apparent when we 

 attempt to formulate the rules for thinnings, etc. There is hardly 

 any line of investigation, observation, and experiment more fruitful, 

 and more needed for the practical purposes of forest planting and 

 management, than to establish this relation of our timber-trees to 

 light-conditions. The rational compositions and form of our plan- 

 tations, their management and reproduction, are based upon this 

 knowledge, and the proper application of it may be well termed 

 ' the essence of forestry.' 



" Observations and experiments, therefore, in regard to the de- 

 pendence of our important timber-trees upon light-conditions, are 

 among the first to be undertaken by the experiment-stations in the 

 forest and in the nursery. 



" Hand in hand with these experiments, will go, of course, the 

 inquiries into the rate of growth and yield before alluded to. If 

 there are old growths at hand, the influence upon the yield of thin- 

 ning with consequent ' undergrowing ' may be ascertained." 



ETHNOLOGY. 



The Prehistoric Race of Spain. 

 Messrs. H. and L. Siret have published the results of their 

 interesting archseological researches in south-eastern Spain, and 

 from their finds trace the history of the primitive people inhabiting 

 that country. The most ancient remains show this people living in 

 the neolithic period ; later on, copper and bronze were used. Thus 

 the researches of the authors give interesting confirmation of the 

 recently established fact, that a copper age preceded the bronze 

 age in most parts of Europe. At the close of the bronze age, 

 silver is first used, and fortified villages occur. At the same time 

 the methods of manufacturing bronze are improved. No iron was 

 found in any of the stations of this people. There were two modes 

 of burial : the dead were buried in large clay vessels, or the corpses 

 were burnt. Weapons, ornaments, tools, food, and earthenware 

 nre always found in the graves, of which about a hundred were 

 explored. The latter have been studied by Jaques. The results of 

 the latter are summarized by KoUmann as follows. First of all, 

 the principal result is of great value: various races occurred among 

 these early inhabitants. No history mentions the name of this peo- 



ple. Since the neolithic period it has remained in the same local- 

 ity. The impression is, that its culture developed continuously 

 without any breaks. Its origin and descent are unknown, but one 

 fact is shown by the forms of the skulls : it was a European people, 

 consisting of European types, the same as live at present in 

 Europe, and which lived at a still earlier period in the caves of 

 Estremadura and at the kitchen-middens of Mugem, or later on in 

 the dolmens near Lisbon. A series of dolichocephalic skulls has 

 been found with an average cranial index of 73.8, and long face. 

 The nose is long and the orbit high. This is the exact counter- 

 part of the long skull of the northern inhabitants of Europe. Be- 

 sides these, Jaques found a short-headed race, also with long faces, 

 high noses and orbits. Their type also occurs frequently in northern 

 Europe. A third race is also brachycephalic, but its characteristics 

 are a broad, flat face, and strong prognathism. Broca considers 

 this type mongoloid. Nevertheless, from a study of the photo- 

 graphs contained in the work, we assume that this race also is of 

 exactly the same type as the European broad-faced, short-headed 

 races, and does not resemble the Mongols. Besides this, a race 

 with broad faces and long heads, the Cro-Magnon race of French 

 writers was found. The fundamental conclusion from these facts 

 is, that in this early period the shores of the Mediterranean were 

 inhabited by several European races. Kollmann considers this re- 

 sult a confirmation of his theory that the migrating European tribes 

 spread early over the whole continent, and that all European peo- 

 ples consist of a mixture of these earliest inhabitants. 



The EvonjTiON OF Ornaments. — There are few branches 

 of ethnology in which the usefulness of extensive collections be- 

 comes more evident than in the study of the development of orna- 

 ment. It is only in collections of this kind that incidental orna- 

 ments can be distinguished from characteristic ones. Since 

 Holmes's admirable study of American ornaments, a number of 

 essays have been published, most of which refer to the islands of 

 the Pacific Ocean. Some time ago we mentioned Dr. L. Serru- 

 rier's study of arrows from New Guinea, which was published in 

 the Internatio?ial Ethnographical Archive. The May number of the 

 Journal of the Anthropological Institicte contains another paper 

 on a similar subject. Mr. Henry Balfdur has studied a collection of 

 arrows from the Solomon Islands, which are on exhibition in the 

 Pitt Rivers Museum at Oxford. The ornamental design of these 

 arrows is invariably found immediately above the joints of the reed 

 of which the shaft is made. It usually consists of a number of 

 incised straight lines, blackened, and running parallel to the shaft, 

 so as to form a band round it. Balfour shows that this design 

 originated in the necessary smoothing-off of the joints. When this is 

 done, the fibrous nature of the substance of the reed causes narrow 

 strips to peel away along the length of the shaft. To prevent this 

 peeling extending far, cross-notches were cut. This was the origin 

 of the ornament, which was later on retained, even when other 

 methods of smoothing off the joints were used. Balfour compares 

 this ornament with those of reed arrows from other countries, and 

 shows that it is probably confined to the Solomon Islands, other 

 methods of ornamentation and of smoothing the joint being used 

 by other peoples. He mentions only a single arrow from South 

 America of a similar description. 



HEALTH MATTERS. 



Diagnosis of Human Blood. 



The diagnosis of human blood is discussed by Dr. Henry Formad 

 in the Journal of Comparative Medicine. Especial attention is 

 given to the methods of examining blood-stains and measuring the 

 blood-corpuscles. 



For testing the question whether a certain substance is blood or 

 not, the spectroscope and chemical re-agents come into play ; but 

 for the recognition of human blood the microscope alone is of any 

 value, and the sole method yet found available with this instrument 

 is that of measurement of the corpuscular elements. The differ- 

 entiation of mammalian blood from that of lower orders of animals 

 is made easy by the fact that in mammals alone is the cell round 

 and non-nucleated. The differentiation between the blood of man 

 and that of lower mammals depends entirely upon the micrometer. 



