140 



HARDWICKE'S SCIENCE-GOSSIP. 



ZOOLOGY. 



The Bonnet Monkey as a Pet.— The illustra- 

 tions of this article were from tracings of two special 

 drawings made from the work published by Mr. L. 

 Upcott Gill, entitled "Notes on Pet Monkeys." 

 We were not aware of this at the time, or we should 

 of course either have duly acknowledged the fact, or 

 not have published them. We apologise to Mr. Gill 

 for the error. 



Struggle between Infusorians and Roti- 

 fers. — Perhaps the following may interest your 

 readers, as the facts appear to prove "intelligence" 

 in animals very low indeed in the scale of life. While 

 examining a large collection of the fresh-water 

 Rotifer (Brachiojius riibens) I observed a lorica, the 

 proper contents of which were replaced by an 

 Infusorian which continually rotated. The Infusorian 

 was ciliated all over, and had a contractile vesicle 

 and nucleus. When swimming, which it did rapidly, 

 with a circular movement, it was spindle-shaped, but 

 capable of great change of form. The contents were 

 clear for the most part, only a little granular at the 

 rear end. A few days after, I found that most of the 

 Rotifers contained one of these guests ; some of the 

 Rotifers being alive, although partly devoured. Very 

 soon the attack was seen. It must be remembered 

 that this Rotifer is a strong and active swimmer. 

 The Infusorian began operations by turning slowly 

 and gently round the Rotifer's foot for some time, 

 and then more rapidly. This appeared to cement 

 the Rotifer's foot to the glass. The Rotifer now 

 lashed about with great vigour in its vain efforts to 

 escape ; but was not able to swim away. The enemy 

 was repulsed many times, but returned to the attack. 

 In about half an hour the Rotifer became exhausted, 

 and the Infusorian got through the opening in the 

 lorica, from which comes the Rotifer's foot. The 

 Infusorian being much larger than the inlet, the 

 following device was resorted to. The front part of 

 the Infusorian was contracted to a mere ribbon, the 

 contents of the animal being pressed into the back 

 part, so forming a globe. The " ribbon " was now 

 easily inserted into the lorica through the hole. 

 Then the contents of the globular part, before outside 

 the lorica, were injected into the " ribbon," making 

 it globular, and thus reversing matters, the bulk of 

 the Infusorian being now inside the Rotifer, the 

 " ribbon " only outside, which was easily drawn in. 

 The Infusorian now assumed a globular form, and 

 rotated itself. The Rotifer's intestine first dis- 

 appeared, the brain and eye last. The Rotifer's cilia 

 moved rapidly for quite half an hour after the entrance 

 of the enemy. Having devoured the Rotifer, the 

 Infusorian divides into two or four new animals, 

 which are exactly like the parent, and swim away 

 swiftly to seek fresh victims, I have not seen these 

 animals attack any other Rotifer, or feed in any other 



way. I have seen the above take place twenty or 

 thirty times, the mode of attack and the result being 

 nearly always the same ; only once or twice did the 

 Rotifer manage to break away. By the way, in the 

 same collection were two forms of the rare Rotifer 

 Notholca, viz. N. acuminata, and a form exactly 

 like Hudson's N. scapha, which he considers to be a 

 marine form only. — R. P. Grace, 



Postscript to "Ravens, Peregrine Falcons, 

 and Puffins at Portland." — Since writing the 

 above I regret to say that the cliff men have taken, a. 

 fourth nest of the same pair of ravens on i6th April ; 

 this time with three eggs, two of which were liglrt- 

 coloured. — J. B. Young. 



The Darts of the Helicid^. — On page go- 

 Mr. Collinge has a note on this subject, and in that 

 note he recommends a correspondent to obtain his- 

 darts by boiling the dart-sacs in a solution of caustfc 

 potash. In writing this note, with great respect to 

 my friend Mr. Collinge, I wish to protest against any 

 such unscientific mode of obtaining darts, as liable to 

 mislead an inexperienced hand. It also seems to me 

 the wrong way to go about gaining an accurate- 

 anatomical knowledge, which every worker in 

 zoological matters should strive to attain, as tending, 

 to make his work more reliable and sound. It is ani 

 easy matter to dissect out the darts from the dart-sac, 

 and it is by dissecting alone that any true and 

 accurate knowledge of these structures can be obtained. 

 I well remember — it was only last Christmas — aj 

 conchological friend bringing me from Nottingham 

 some things which he had obtained by the caustic 

 potash process from H. virgata which he thought 

 were darts ; what they indeed were it was not 

 possible to say. In my friend Mr. Heathcote's note 

 (the one before Mr. Collinge's) the word sheet is- 

 misprinted for shell, and the word sheets for shells. 

 In a recent number of " Life-Lore" there is a fairly 

 good and accurate article on darts from the pen o£ 

 Mr. Standen which I would advise C. A. W. to read. 

 So far as I know, Mr. Standen's article is trust- 

 worthy, except when he goes a little away from his- 

 subject, and mentions that some "crystalline stylet "' 

 is found in the stomach of some snails. I am afraid 

 that here Mr. Standen means Anodonta cygnea, and 

 other lamellibranchs, which can scarcely be classified 

 as snails. He seems to me here to be making a 

 reference to the researches of Hazay and Krukenberg 

 (Mai. Bliitt. iii. 18S1, p. 196, and Vergl. Physiol. 

 Vortriige, ii. p. 63, 1882) on its being found in the- 

 Unionacea. And as this is a peculiarly interesting 

 point, I ask Mr. Standen to definitely state his 

 meaning through the medium of these pages. If a> 

 crystalline style has been found in any portion of the 

 enteric tract in any Gastropod, I would be very much 

 obliged to him for the reference or references, since I 

 am ignorant of any such. — J. IV. Williams. 



