July 17, 1884] 



NA TURE 



265 



which either the one or the other is dredged is not stated. A 

 still continued depression takes us through Green Mud to the 

 Chalk Marl, which apparently is a true Globigerina ooze 1 ; and 

 this passes into a true White Chalk. The White Chalk is 

 the result of still farther depression, for it overlaps the other 

 deposits, and as the great change in the character of the sedi- 

 ment cannot have been due to the shallowing of the sea, and 

 yet must have had a cause, we must conclude it was due to deep- 

 ening. Its enormous extent and thickness and great purity pro- 

 claim it in fact to be an oceanic deposit, and there does not appear 

 to be anything with which it can be compared except Globigerina 

 ooze. 2 The White Chalk of England could therefore only have 

 been deposited under the conditions of depth, or remoteness from 

 land under which the deposit of Globigerina ooze is possible. 

 If Globigerina ooze is not a "terrigenous" deposit, Chalk is not, 

 and it does seem singular that it should be classed as such by 

 Renard and Murray, unless indeed they are prepared to point to 

 an area in which a similar terrigenous formation is taking place 

 at the present day. If genera now confined to shallow-water are 

 present in it, it only proves that there must have been deep-water 

 representatives of those genera in the Cretaceous ocean. This 

 is in fact probable from at least two considerations, the one that 

 the examination of the abyssal fauna is still relatively "ex- 

 tremely slight and cursory," as Dr. Gwyn Jeffreys has so amply 

 admitted in the address he refers me to. It is probable that 

 thousands of casts of the dredge have been made in the littoral 

 zone for one in the abyssal zone, and we are, therefore, not in a 

 position yet to say that any genus may not have representatives 

 in the latter. The second consideration is far more important. 

 Dr. Gwyn Jeffreys states that "all of them (the Cretaceous 

 Mollusca) are evidently tropical forms." Now there is strong 

 evidence from the present distribution, and the deposition of 

 the Chalk, that the sea did not communicate with Arctic seas. 

 Prof. Prestwich, in his anniversary address to the Geological 

 Society, pointed this out in 1871. But even if it had, the 

 Arctic climate during the Cretaceous period was a warm one, 

 and for these two reasons, or either of them, the abyssal depths 

 of the Chalk ocean were probably higher in temperature than 

 they are now, while the temperature of the more littoral zones 

 may have been almost tropical. Heat and cold seem greater 

 factors in the distribution of Mollusca than depth of water. 

 Relatively cold-loving genera or species of genera that could 

 only have found the necessary temperatures then at great 

 depths, may now find suitable habitats in shallow water. 

 The "tropical Mollusca" of the Chalk might for this reason 

 have been able to live at much greater depths when such 

 were warmer, but are of necessity now restricted to those in 

 which suitable temperatures are to be met with ; and since these 

 are now all relatively shallow, Dr. Gwyn Jeffreys may be quite 

 right in saying that these extinct species have a shallow-water 

 facies, without our being obliged to accept his inference that the 

 Chalk sea was a shallow one. But if we accept the Mollusca pure 

 and simple as a test of depth, their evidence as adduced is un- 

 trustworthy owing to the association together of those of the Gray 

 Chalk and the Irish Chalk band of Kilcorrig. Eliminating 

 these, we have no patelloid shell left but Hipponyx, and the 

 Chalk species was completely different in habit to anything living. 

 I do not know the Chalk Chama (if the Irish form, this is a 

 limpet) or Pinna, and these must be very rare and even pos-ibly 

 drifted shells. The unextinct characteristic genera are in fact 

 reduced to Terebraticla, Lima, Pecten, Armttssium, and Spon- 

 dylus, and of these all but the latter are stated, in the address I 

 am referred to, to have been met with in water 1450 fathoms 

 deep. 3 



It would be impossible to dispose of a question of such im- 

 portance in a mere letter. My object in writing is to elicit, if 

 possible, the exact grounds on which Messrs. Murray and 

 Renard base their statement that the Chalk was a shore de- 

 posit ; and it would also be exceedingly useful if Dr. Woodward, 

 Dr. Duncan, Mr. Davidson, and Mr. Carpenter would give 

 their opinions, and the grounds on which they are based, on 

 the probable depth required by each of the Cretaceous groups, 



nly composed, according to Murray, of 40 

 le, oxides of iron and manganese, and argilla 



1 Globigerina ooze is m; 

 per cent, of carbonate of li 

 matter. 



2 Of reef-building corals there is not a trace either in it or in any 

 poraneous formation, and nothing can be more opposed to all evidente than 

 the supposition advocated, it will be remembered, by Wallace in " Island 

 Life." 



3 There are few traces in the English Chalk of any Mollusca except those 

 that possessed calcue shells, and what the rest were like as a group no one 



respecting which they are the chief authorities. Dr. Gwyn 

 Jeffreys is the only one who has contributed anything definite 

 towards a solution of this most important geological problem, 

 and for this, while believing other conclusions may be deduced 

 than those he has arrived at, I and many other geologists heartily 

 thank him. J. Starkie Gardner 



Animal Intelligence 



The following notes of facts observed in New Zealand may 

 be thought of interest ; in some way they may serve to illustrate 

 Mr. Romanes' work on " Animal Intelligence " : they are sub- 

 mitted without making an attempt to distinguish where they may 

 overlap the fine line between instinct and intelligence. Cases 

 which may show apparent intelligence or the reverse are recorded, 

 that we may arrive at a clearer view of the truth in animal life. 



The dog cannot be passed over without mention ; he is always 

 to the fore where intelligence is required. Here, where sheep 

 occupy so large a share in the employment of country people, 

 the colly may be seen daily exhibiting its wonderful talents in 

 controlling the movements of its simple charge. Its achieve- 

 ments are too numerous for recital. 



Amongst birds we found the quail-hawk (F. nouce-zelandice), 

 quickly learnt to avail itself of the property of the new settlers ; 

 it attacked both poultry and pigeons with the greatest determin- 

 ation directly these foreign birds appeared at the stations and 

 outlying farms. The harrier (Cirens approximate), more stealthy 

 than the falcon in its depredations on the poultry, perhaps not 

 less destructive, is careful if possible to convey its prey to a quiet 

 spot free from interruption, where its meal can be finished at 

 leisure in security. It found out the use of cornricks and hay- 

 stacks as mouse-preserves ; in some places several harriers 

 might be seen at one time perched on the thatch carefully watch- 

 ing for vermin. It killed the rabbit ; the swift-footed hare it 

 found out could be hunted to best advantage in company : several 

 of them would join in the pursuit, wheeling softly with every 

 double of the distressed animal, till, quite exhausted, it lay 

 stretched out in death. The harrier, the gull, the tern, all used 

 to put in their appearance after the large grass fires of former 

 days had swept miles of country ; lizards, as they crept from 

 under the stones laid bare by fire, seemed the attraction for 

 all these birds. One autumn, when laid up with rheumatism, 

 lights were brought into the room rather early. I often heard 

 the sound of scratching on the window-glass, and found it 

 proceeded from the efforts of an owl (Athene, N.Z.) to secure 

 moths from the lighted-up window-panes; this was repeated 

 for many evenings during parts of the months of April and May, 

 so that I always expected my evening visitor. As a mouser this 

 same species learnt the value of stations near barns and stacks ; 

 frequently, many scores of times, have I seen it keeping its 

 solemn watch on a post or rail of the barnyard (see Zoologist, 

 1873, p. 3621). The kakapo or night-parrot (Slringops) shows 

 intelligence in its nesting arrangements : the chamber at the end 

 of a long tunnel is covered at the bottom with a great accumu- 

 lation of excreta ; each of these is an inch or more in diameter 

 — the bird is a vegetable feeder — the warmth derived from this 

 mass is secured by the young, reversing the proverb, "It is an 

 ill bird that befouls its own nest." 



The kea (Nestor notabilis) (see Nature, vol. iv. p. 489). 

 Its rapid development of a change of habit that led it to 

 destroy sheep has proved very disastrous to many mountain 

 sheep-farmers. It is remarkable that the discovery of the 

 excellence of kidney fat should become known almost 

 simultaneously through a long tract of country ; how were 

 beginners instructed to dig their beaks into the wool just 

 above the sheep's kidneys ? Horses have been wounded by 

 them in the same part ; all this shows a ready means of spread- 

 ing information. One of the writer's sons snared a few fine 

 specimens, but they very soon became aware of the snare and 

 promptly avoided it. When thrown at, they learn to dodge the 

 stone, just ducking or moving aside. One, imprisoned under an 

 inverted bucket, after a time thrust its strong beak between the rim 

 of the bucket and the floor, turned over the bucket and escaped. 



The two cuckoos Endanymis and Chrysoeoccyx offer a pro- 

 blem of peculiar interest as regards migration. The journeys 

 they undertake and accomplish across wide expanses of ocean 

 are amongst the most courageous and trying physical feats in 

 bird history: "as bold as a hawk," "as brave as a game- 

 cock," are proverbs that are befitting ; but these birds deserve as 

 much recognition for their adventurous daring. 



When either of these species is observed flying, it will be 



