116 



SCIENCE. 



[Vol. IV., No. T9. 



can be brought to each side in succession. 

 The depth of the cavern seems to have little 

 effect. I have called up the occupant from 

 a burrow which subsequent examination has 

 proved to be eighteen inches deep. Unless 

 she has been deceived several times, she usu- 

 al^ runs up rapidly, and will occasionally snap 

 at the end of the straw. While experimenting, 

 it is hardly possible to avoid introducing frag- 

 ments of the jtower, or adherent particles of 

 earth, and it occurred to me that these might 

 be the call to which the spicier responded ; but 

 sand from an ant-hill, sprinkled in freely, had 

 no effect. 



Mrs. Marj T Treat, writing of another species 

 of Tarantula, says that all food-remains were 

 ejected in the same waj T as the earth pellets. 

 Tarantula arenicola is not so neat. The earth 

 beneath old burrows is often darker than the 

 walls, and densely filled with fine rootlets. It 

 is probably darkened and enriched by the spi- 

 der's excrement and food-remains. From bur- 

 rows in the field it is the rule to take masses 

 of debris, which consist of the spider's exuviae, 

 the heads and legs of ants, the elytra and 

 other chitinous parts of beetles, with frag- 

 ments of insect-wings. It seems that the 

 dead and empty bodies are torn to pieces, and 

 scattered at the bottom. This was done by a 

 captive which would not dig, but which ac- 

 cepted maimed flies. After extracting the 

 juices, the spider tore the body into fragments 

 so small that only careful search could find 

 them. In but two instances have I observed 

 an ejection of food-remains. A mutilated fly 

 was seized from a tower, and twent} T -four hours 

 later I did find what appeared to be the desic- 

 cated remains. In the second case, two spi- 

 ders were fighting fierceby when set free at 

 evening, near the burrow of a small specimen 

 in the garden. During the night the occupant 

 of the burrow was dislodged, and the van- 

 quished spider had been dragged into the pit 

 which the conqueror had enlarged, and 

 whence, in the course of the morning, frag- 

 ments of the dead body were thrown out, 

 among them the abdomen severed from the 

 thorax, but not otherwise mutilated. Occa- 

 sionally, also, an elytron can be found near a 

 tower in the field. 



This disposition of remnants is somewhat re- 

 markable ; since spiders in general are cleanly, 

 and since this one is particularly intolerant of 

 intrusive objects. A straw or stem dropped 

 into the burrow is immediately carried up, and 

 tossed away. The only instance observed, 

 where a young spider ascended backward, 

 was when trying to get a heavy stick out of 



the pit : having lifted in vain, she attempted 

 to pull. 



Noticing the fondness for ants, a number 

 of bran-cracker crumbs were sprinkled at a 

 distance of six inches from the tower, and an 

 ant was soon struggling under a load larger 

 than itself. Suddenly the spider on the tower 

 started, erect and rigid : she leaped to the 

 ground, she ran six inches, she seized that 

 bit of cracker, and retreated with it to her bur- 

 row, leaving the emmet on its back in the 

 dust. For two hours she remained below. 

 The following day I twice witnessed the same 

 performance. The spider once overran the 

 crumb, and so lost it. At the third time, the 

 piece of biscuit became wedged in the tower 

 as the spider was running in backward, and 

 I plainly saw her nibbling at it. During a 

 momentary absence for forceps to remove it, 

 to examine for marks of mandibles, the spider 

 carried it down and out of sight. The frag- 

 ments were not touched, except as they were 

 being borne about by the ants. Is it usual 

 for spiders to take any but animal food ? 



Dr. Alfred C. Stokes. 



THE EXPLORING VOYAGE OF THE 

 CHALLENGER. 



(Second Notice.) 1 

 Professor Herdman has published the first 

 part of his memoir upon the Tunicata (vol. 

 vi., 296 p., 37 pi.), which treats solely of the 

 ' Ascidiae simplices,' the composite and pe- 

 lagic forms being reserved for future consid- 

 eration. From the historical preface to the 

 index, this report is a model of systematic ar- 

 rangement ; the bibliography, and the chapter 

 on anatomy and classification, being worked 

 out with especially elaborate care. The most 

 important generalizations reached are: 1. 

 These simple ascidians are not numerous in 

 the northern hemispheres, are comparatively 

 scarce in tropical latitudes, and attain the 

 greatest abundance in southern temperate re- 

 gions ; 2. Although simple ascidians occur in 

 veiy deep water, and are fair by represented in 

 the abyssal zone, they are chiefly a shallow- 

 water group, and are most numerous around 

 coasts in a few fathoms of water ; 3. The oc- 

 currence of simple ascidians does not depend 

 upon temperature or character of bottom. The 

 discussion of questions affecting the Tunicata 

 as a class is reserved for the second part of the 

 report. The phylogenetic table on p. 286 is 

 of great interest. 



i See No. 66. 



