650 



NATURE 



[July 21, 192 1 



almost entirely of flake-scars, while the keel, or 

 carina, is not a very marked feature. 



The implement illustrated in Figs. 4 and 4A is quite 

 comparable, in its general outline and form, with that 

 shown in Figs. 3 and 3A. Both these specimens, 

 made from "chunks " of quartzite struck from still 

 larger masses, are of great interest and importance 

 as showing a transitional stage between the typical 

 rostro-carinate form, with its prominent and func- 

 tional keel, and the "batiform " Palaeolithic imple- 

 ment, in which, while the simple triangular section is 

 retained, the keel has become "depressed" and 

 almost obliterated, thus ceasing to have any functional 

 purpose. I have already described how, by the 

 gradual "depression" of the carina, the rostro- 



FIG4- 



Riewr uTi^Au vitw 



Figs. 4 and 4A.— M ssivc quaitzite implement from Uganda, 

 of a form transitional between the rostro-carin«te and the 

 " batiform " Palxolithic specimens. 



carinate developed into the "batiform" implement 

 of Early Palaeolithic times (Phil. Trans., series B, 

 vol. ccix., 1920). 



The specimen illustrated in Figs. 5 and 5A repre- 

 sents another form of the rostro-carinate, in which 

 the keel extends continuously, and approximately, in 

 the middle line, from the anterior to the posterior 

 region of the dorsal surface. I have suggested in 

 my Phil. Trans, paper that such specimens might 

 have been used as "side-choppers," the more or less 

 flat ventral area resting against the palm of the hand, 

 while the prepared keel would be utilised as a cutting 

 edge. It is, of course, posisible that, in addition to 

 such use, implements of the type shown in Figs. 5 and 

 5A might be used as picks. Figs. 6, 6a, and 6b illus- 



FlC 5« 



t)ORSALV\EV< 



^^^.^OZL 



Figs. 5 and 5 a. — Quartzite implement of rostro-carinate form from Uganda, 

 in which the keel extend^; over the whole length of the dorsal surface. 



trate a specimen of well-known Early Palaeolithic 

 type, to which, at the suggestion of Sir Ray 

 Lankester, I have given the descriptive name 

 " platessiform." In this form of implement, in which 

 the keel of the rostro-carinate becomes one of the 

 cutting edges, while the more or less flat ventral sur- 

 face is flaked awav to form another cutting edge 

 opposite to the keel. (Phil. Trans., series B, vol. ccix., 

 1920), the method of manufacture is entirely different 

 from that adopted in the making of a "batiform '' 

 implement. In the former the specimen is, as was 

 pointed out by Sir Ray Lankester, so to speak, 

 compressed from side to side, and the keel retained 

 as a leading feature in its development, while 

 in the latter the implement is, as it were, de- 

 pressed—from above downwards — and the keel be- 



NO. 2699, VOL. 107] 



comes functionless. The specimen illustrated (Figs, 6, 

 6a, and 6b) is of interest as showing, as do so many 

 Early Chellean implements of similar form found in 

 this country, the retention of portions of the original 

 striking platforms (C and D in Figs. 6a and 6b), the 

 dorsal and ventral surfaces of the ancestral rostro- 

 carinate form. 



From the above description it will be seen that I 

 am of opinion that the specimens found by Mr. 

 Wayland in Uganda are "related" to the rostro- 

 carinate implements found beneath the Red Crag of 

 East Anglia. It is clear, also, that the method of 

 manufacture adopted in the case of these Uganda 

 specimens is the same as was followed by the Early 

 Chellean people living in this part of the world, and 

 described by me in the Phil. Trans, paper quoted 

 above. 



The large collection made by Mr. Wayland in 

 Uganda comprises certain well-made hand-axes, 

 scrapers, and other forms of implements, of which, 

 no doubt, a detailed description will appear in due 

 course. But the majority of the relics found are, it 

 seems, massive examples of Early Palaeolithic arte- 

 facts, which appear to me to be very similar, in their 

 forms, size, and technique, to thosei recently found 

 by me at Cromer (Nature, February lo, 192 1). Mr. 

 VVaj'land is to be warmly congratulated upon the 



¥lc,^i. 6, 6a, and 6b. — Quarlziie implement of Early . 

 Palaeolithic "platessiform" type from Ug.inda, 

 •bowing portions of the original striking plat- 

 forms retained (C and D in Figs. 6a and 6b). 



important discovery he has made, which throws a 

 new and welcome light upon the antinuity of man 

 in Uganda. The outlines of the implements figured 

 are not drawn to any special scale, but the approxi- 

 mate dimensions are indicated by the side of each 

 drawing. J. Reid Moir. 



One House, Ipswich. 



Measuring with High Powers of the Microscope. 



Under a high power it is extremely troublesome 

 to move the object so that one of its boundaries 

 coincides exactly with a division of the micrometer- 

 scale. But when the object is small this very greatly 

 increases the accuracy ; otherwise two estimated 

 fractions of a division may constitute the greater part 

 of the length measured. 



Coincidence may be effected easily and with great 

 exactness by gentle lateral pressure from the tip of 

 the finger on the tube of the microscope ; in this way 

 the boundary of a well-defined image can easily be 

 made to bisect a black line on the micrometer. If a 



