i=?o 



HARDWICKE'S SCIENCE-GOSSIP. 



epidermis ; 3, a series of conferva-like arrangement of 

 cells, making a free ventilation into the whole of the 

 lozenge-shaped divisions for air, whilst 4 is a solid 

 layer of cells, rising into a wall on each side. The 

 loose tissue, 3, in the centre, only contains chloro- 

 phyll. 



Glancing over the thallus, a quantity of cup-like 

 bodies are easily visible (fig. 92) called con- 

 ceptacles, these contain gemmae, or buds. When 

 viewed with a low power, the edge is seen to be 

 fringed, in fact they are objects of singular beauty. 

 Detach a few of the gemmae, and slightly magnify 

 (fig. 89), they are composed of two or more layers 

 of cells, and are round or oblong in outline ; event- 

 ually they are washed out by rain to some damp 

 spot, and grow rapidly into mature plants ; thus the 

 thallus of the Marchantia is often, when it appears 

 to be luxuriant, merely a thickening of young plants, 

 produced from the gemmae. Examine the upper 

 surface of the thallus, under a Coddington lens, to 

 detect the slight elevation of the epidermis which is 

 the first growth of the conceptacle ; then cut 

 sections of these, to observe the formation of the 

 gemmae. Fig. 93 is a sect, through the conceptacle ; 

 they first appear as minute globular cells supported 

 on other cells, as a kind of footstalk ; 1 is the single 

 layer of epidermal cells, 2 is the gemmae, in various 

 stages of growth. These single cells next undergo 

 rapid change, until they become perfect buds, when 

 they lie detached from the footstalk in the con- 

 ceptacle. We find another mode of reproduction by 

 fertilised oospores in the Liverworts. The anther- 

 idia and archegonia are developed on special erect 

 branches, more rarely on the same stalk. Search the 

 mature thallus for the little umbrella-like stalks, 

 which occur abundantly in summer. (Fig. 94.) 

 Prepare a section of one, in the early stage, as 

 observed in fig. 95. No. 1 is the thick frond, or 

 thallus ; 2, openings, beneath which occur the 

 antheridium. The archegonium, or female organ, 

 is found on a distinct receptacle, or star-like 

 stalked bodies. (Fig. 96.) A section cut through the 

 receptacle will result in making an acquaintance 

 with the ripe archegonia. (Fig. 97.) No. 1 is the 

 neck connecting No. 2, a central cell, in which is 

 seen the oosphere with nucleus, No 3. When the 

 antheridium bursts it frees the antherozoid, which 

 is a spirally coiled thread, furnished with two long 

 cilia, these find their way down the neck of the 

 archegonia ; after impregnation the sporogonium 

 is formed, containing spores. The sporogonium is 

 furnished with elaters, peculiar long cells with brown 

 spiral bands. The spore when germinating gives 

 rise to the pro-embryo, on which the future plant 

 arises from a bud on its surface. 



J. F. R. 



Can any reader name me a book, with price, on 

 Aphides and other micro slides ? — William R. Wells. 



NATURAL HISTORY JOTTINGS. 



Further Observations on the Ivy Aphis and- 

 its attendant Ants. 



SEPTEMBER 10th, 1SS0.— To-day, on examining 

 a number of small plants of ivy that have been 

 planted in the interstices of the additional height of 

 wall that has been added to the highest terrace- 

 wall on the Measure Hill, St. John's Cemetery, 

 Elswick, I observed that about a dozen of them were 

 more or less infested with an apterous aphis clustered 

 around the stem, leaf-stem, and from the leaf-stem, ex- 

 tending on to the under side of the leaves, and that most 

 of these clusters were attended upon by a small red ant 

 (Myrmica), which is here, along with a larger black 

 ant (Formica), pretty plentiful in its season. What 

 these ants were after I could not at first make out 

 certainly ; they were neither injuring the aphides, 

 nor attempting to carry them away, as I had very 

 frequently seen ants doing with much larger and 

 more powerful insects. On a closer examination with; 

 a lens, however, I found that the ants were running 

 about over the small groups or clusters of the stout, 

 dull, reddish-purple apterous aphides, gently and 

 rapidly whipping them, as it were, with their long and 

 versatile antennae or horns, though evidently not dis- 

 turbing them in the least, much less injuring them ; 

 and, on several occasions, I distinctly observed an 

 aphis respond to this treatment, elevate the posterior 

 part of its body, and emit a drop of pellucid liquor from 

 the very tip of the abdomen, not the cornua, which 

 was immediately sipped up by one of the attendant 

 red ants : here then was an exhibition of the aphis- 

 milking proclivities and capabilities of the ants, 

 accounts of which I had early read, but which I had 

 never before been so fortunate as to observe. 



On many subsequent occasions, up to Oct. 12th, I 

 visited these aphis-infested ivy-plants, and found the 

 aphides in numbers, and invariably attended on and 

 caressed by the red ants, which I frequently observed 

 repaid for their attentions and labour by the yield- 

 ing up by the aphides of a minute drop of the 

 coveted liquor. 



Aug. 31st, 18S2. — It was on the 21st inst. that, 

 after having looked over my Natural History notes, 

 and found that there was much interesting information 

 jotted down respecting several species of aphis, or 

 plant-louse, I determined on drawing up a short 

 paper on the subject, and thought it desirable to make 

 some further investigation of the habits and surround- 

 ings of the ivy aphis, if haply it were yet in existence, 

 as I thought it quite possible it might have perished in 

 the wreck and removal of the greater portion of the 

 terrace-wall upon whose plants it had alone been 

 observed. However, on going to the spot, there it 

 again was, though only upon one of the few remaining 

 small plants ; and, there, too, were the attendant red 

 ants, caressing and milking the small group of 



