394 



KNOWLEDGE. 



October, 1913. 



probably excrementitious, are often to be seen marking the 

 path. An interesting observation refers to a case where the 

 path followed went up four posts and down the other side 

 instead of keeping along the level ground 1 



At critical places, or when danger threatens, the soldiers 

 form a double file guarding the march of the workers, and 

 they all face outwards. From an ampulla in their head they 

 squirt out viscous fluid in the face of offensive true ants like 

 Oecophylla. The nocturnal expeditions have the object of 

 collecting lichens, debris of leaves, and apparently some black 

 material from the humus. 



HABITS OF THE AGAMA.— Dr. W. A. Lamborn gives 

 an interesting account of the habits of the common West 

 African lizard, Agama colonorum. There seems to be a 

 great disparity in the numbers of the sexes, and each male is 

 attended by several females, sometimes six or seven, who 

 behave with remarkable subservience towards their lord 

 and master. " The male's responsibilities seem to be in excess 

 of his capacities, so that the females are forced to resort to 

 various artifices to secure their share of his attentions." The 

 males are exceedingly combative, and the intrusion of one into 

 another's preserves usually leads to a battle. " The tail is the 

 offensive weapon, and to bring it into action the males take up 

 a position parallel to each other, but head to tail. Each seeks 

 to overcome the other, not by a number of strokes, but by a 

 single well-directed blow." The female lays the eggs, in a 

 cluster of three or four, in a burrow in the ground, and covers 

 them with earth. The lizards are usually insectivorous, but 

 will eat lettuce, tomatoes, and the like, in the dry season. 

 Their voracity is remarkable. On one occasion Dr. Lamborn 

 dropped no fewer than eighteen butterflies before a male 

 Agama, and all were consumed in ten minutes. 



IN VERY DEEP WATERS.— Professor Louis Roule has 

 recently described a new abyssal fish, Grimaldichthys 

 profundissimus, gen. et sp. nov., which was dredged by His 

 Serene Highness the Prince of Monaco from a depth of 

 6,035 metres to the south-west of the Azores. One of the 

 features of this new form is that all the rays of the pectoral 

 fin are free and filamentous. The rather dangerous title 

 profundissimus indicates that up to date the depth inhabited 

 by this fish is greater than that recorded for any other. 



HATCHING OF CROCODILES' EGGS.— Many years 

 ago (1899) Dr. Voeltzkow noticed that unhatched crocodiles 

 (Crocodilus madagascariensis) utter a cry from within the 

 egg — a cry that can be heard even when the eggs are covered, 

 as in nature, by one to two yards of sand. The sounds are 

 produced with the mouth closed, as we produce hiccough 

 sounds. Dr. Voeltzkow writes : — " This crying of the young 

 can be induced by walking heavily past the receptacle con- 

 taining the eggs (a box in the study), by knocking against it, 

 by taking an egg in the hand and turning it ; in fact, any shock 

 causes the young one to lift up its voice in the egg. As the 

 female visits the nest almost daily in order to convince herself 

 of its orderly condition, her passage from the water to the 

 nest and back shakes the ground and induces the production 

 of sound by those young ones which are sufficiently developed. 

 Thereupon the old one scrapes the sand out of the pit and 

 presently the young emerge." Dr. W. A. Lamborn has 

 recently made similar observations in regard to Crocodilus 

 niloticus at Lagos. Croaking noises were heard from below 

 a dry path, and when he dug down he found thirteen eggs, all 

 chipped save a bad one, at a depth of about eighteen inches. 

 All the young crocodiles hatched out within half an hour of 

 being dug up. 



SOLAR DISTURBANCES DURING AUGUST, 1913. 



By FRANK C. DENNETT. 



August has been marked by a continued absence of 

 activity on the Solar disc. On two days only (11th and 28th) 

 tiny spotlets or pores were visible, on eight others (10, 14, 

 16-19, 27 and 29) faculae were seen, and on the remaining 

 twenty-one days the sun appeared free from disturbance, 

 unless exception be taken to a greyish patch some thirty 

 hours past the central meridian, in north latitude, seen on the 

 24th. The longtitude of the central meridian at noon on 

 August 1st was 87° 10'. 



By some strange mishap the spot groups and faculae for 

 July have not reproduced on the diagram in the September 

 number of Knowledge ; they have therefore been inserted in 

 our present chart, the faculae being distinguished by the 

 letter a. 



On August 11th a tiny pore was visible, amid faculae, 

 advancing from the north-eastern limb ; it was too minute for 

 measurement, but was approximately in the position marked 



by a cross in longitude 248°, N. latitude 10°. Only seen on 

 one day. 



On the 28th a minute pore with faculae was seen some 

 40° round the eastern limb — approximately in longitude 40° — 

 cloud intervened before exact measurements could be made. 

 Faculae were visible on the 10th some 35° from the south- 

 western limb. On the 14th a small double facula, situated 

 just south of the area of Group No. 9, closing up to the 

 western limb. On the 16th a small bright cloud seen less 

 than 20° from the North Pole, some three days past the 

 meridian. On the 17th and two following days a facula seen 

 some 8° S. latitude, in longitude 155°. On the 27th a tiny 

 facula was almost on the meridian about 18° from the South 

 pole ; also a brilliant knot in N. latitude 34°, longitude 21° ; this 

 remained visible ou the two following days. 



Our chart is constructed from the combined observations 

 of Messrs. J. McHarg, E. E. Peacock, and F. C. Dennett. 



DAY OF AUGUST, 1913. 



