242 THE NATURAL HISTORY EEYIEW. 



recondite problem of genetic biology, accurate observations on the 

 races of animals and plants are invaluable, and in this sense no 

 observation can be too minute, no description too precise, no cha- 

 racter too trifling, provided it exist in nature. For the ordinary- 

 student of nature it seems to us that these minute details are un- 

 necessary, because they are doubtful, fluctuating, and uncertaia. To 

 put into the hands of beginners an elementary work in which these 

 forms are elevated to the rank of species, without at the same time 

 drawing his attention to their uncertainty, seems to us to convey 

 an erroneous impression of the state of our knowledge. We get a 

 more accurate picture of the British flora, by restricting it to the 

 Linnean types, than we shall possess when it is worked out in all 

 its details, on the principles of M. Jordan. 



©iliiginal ^iifi^Iij.^. 



XXII. — On Synostosis of the Cranial Bones, especially the 

 Parietals, regarded as a Eace-character in one class op 

 ANCIENT British AND in African Skulls.* By JohnThurnam, 

 M.D. 



Obliteration of the sutures of the skull and synostosis of the 

 cranial bones has of late received much attention, more especially 

 from those distinguished Grerman anatomists, Yirchow, Lucse, and 

 "Welcker ; by whose labours the progress of a rational and scientific 

 craniology has been so much promoted. 



I propose to consider this subject in reference especially to one 

 class of ancient British skulls, viz. those from the chambered and 

 other long barrows of the stone period. I may here observe that the 

 general form of these skulls is elongated or dolichocephalous, and 

 that they are strikingly distinguished from the brachycephalous 

 skulls from the circular barrows of the bronze period; not only by 

 their general form, but also, as would appear, by their greater ten- 

 dency to early and premature obliteration of the sutures. Tlie mere 

 fact of such a distinction in the skulls derived from two classes of 

 ancient British tombs is of sufficient interest to deserve notice ; but 



* Read at the Meeting of the British Association at Bath, Sept. 1864; and 

 here printed with additions and corrections. 



