& 
a ( 5 e 
NATURE 
May 22, 1873] 
_ provide for itself, the Nauplius has become degraded into 
a mere skin; in Zz<za this larva-skin has lost the traces 
of limbs, and in Phi/oscia it is scarcely demonstrable.” 
- Once more, the Echinodermata in most cases “go 
through a very well-marked metamorphosis, which often 
has more than one larval stage. The distinctive charac- 
ter of the metamorphosis appears to be the possession by 
the larve of at least a mouth and pharynx, which, whether 
absorbed or cast off, is never converted into the corre- 
sponding organs of the perfect Echinoderi developed 
inside of the provisional organism. The mass of more or 
less differentiated sarcode, of which the larva, or pseud- 
embryo, as opposed to the Echinoderm within it, is made 
up, always carries upon its exterior certain bilaterally- 
arranged ciliated bands, by the action of which the whole 
organism is moved from place to place, and it may be 
strengthened by the superaddition to it of a framework of 
calcareous rods,”* 
Thus Fig. 39 represents a larva of Echino-cidaris, after 
Muller;+ The body is transparent, ,5; in length, shaped 
somewhat like a double easel, but with two long horns in 
front, which, as well as the posterior processes, are sup- 
ported by calcareous rods. These larve swim by means 
of minute vibratile hairs, or cilia. They have a mouth, 
stomach, and in fact, a well-defined alimentary canal, but 
no nerves or other organs have yet been discovered in 
them. After swimming about in this condition for 
- awhile, they begin to show signs of change. An involu- 
_ tion of the integument takes place on one side of the 
_ back, so as to form a pit or tube, which continues to 
deepen till it reaches a mass or store of what is called 
blastema, or, as we may say, the raw material of the 
animal body. This blastema then begins to grow, and 
gradually assumes the form of the perfect Echinoderm. 
In doing so it surrounds and adopts the stomach of the 
larva, but forms for itself a new mouth or gullet, throwing 
off the old mouth, together with the intestine, the cal- 
ee rods, and in fact all the rest of the body of the 
a. 
Fig. 40 represents a larva probably of Echinus lividus, 
from the Mediterranean, and shows the commencement 
of the sea egg within the body of the larva. The capital 
letters denote the different arms, a is the mouth, @’ the 
zsophagus, 4 the stomach, J’ the intestine, f the ciliated 
lobes or epaulets, ¢ the young sea-egg. 
JouHN LuBBOCK 
(To be continued.) 
EXTIRPATION BY COLLECTORS OF RARE 
PLANTS AND ANIMALS 
» ee Legislature, having very properly provided for the 
preservation of small birds, might extend its protec- 
tion to other animals and to plants ; for although it would 
be inexpedient to prevent individuals from taking rare 
insects and botanical specimens, it is surely expedient to 
deter persons or societies from offering premiums which 
are leading to the extirpation of such species. 
Some years ago a judicious and formal protest against 
this culpable practice was published by many of the most 
eminent British botanists, and it has constantly been de- 
plored by all true lovers of natural science. The respected 
president (the Rev. Dr. Mitchinson) of our East Kent 
Natural History Society, in his address at the last annual 
meeting thereof at Canterbury, made such strong observa- 
tions on the subject as might raise the question whether local 
societies may not do as much harm by promoting the extir- 
pation of rare plants and animals as good in other respects ; 
and I have always been insisting, at the meetings of the 
same society and elsewhere, that it is our duty to cherish, 
and not destroy the precious plants and animals of the 
* “ Rolleston—“ Forms of Animal Life,” p. 146. 
+ Uber die Gattungen der Seeigellarven. Siebente Abhandlung. Kon. 
~ Akad. d Wiss, zu Berlin. Von Joh. Miiller, 1855, Pl. iii. fig. 3. 
2 
73 
district. Whenever a rare plant or win sexi bired 4 
those meetings, we have alw+ys a wai! 2 out its haviag 
been “not long since often se n, thougt 0 as 
pearing.” A chief cause of this is the de» lorable rapaciy 
of collectors of and traffickers in specimens; since the 
preposterous notion prevails that botany and entumolozy 
consist in a recognition of the mere physiognomy, without 
the least regard to the physiology, of species, and being 
able to call them by their scientific names. 
And so it will be while local societies continue to en- 
courage such errors, instead of promulgating the essential 
principles of botanical or entomological science, and ob- 
structing the injurious operations of mere collectors or 
pretenders. And this desirable end, so far as regards 
taxonomy, might be easily attained without the least 
harm to rare species, Prizes for the best display, illus- 
trated by microscopic drawings and preparations of the 
generic and specific characters of sections or the whole 
of many natural orders would afford really good tests of 
the industry and attainments of the candidates. For 
example, why not try for this purpose the Willows, Grasses, 
or Sedges? Two of these orders have the further recom- 
mendation of being of great economic value. Again, as 
specific distinctions seem to be the ultimate aim of these 
societies, certain cells or tissues, such as the pollen, epi- 
dermis, hairs, and stomata, would afford good subjects 
for investigation in this point of view, as would also 
raphides and other plant-crystals, and very likely disclose 
valuable characters not yet recognised in the books of 
systematic botany. 
I have been led to these remarks by the increasing fre- 
quency of the practice now deplored. As the “ West 
Kent Natural History, Microscopical, and Photographic 
Society” is much and deservedly respected, and exercises 
justly considerable influence in its department, an extract 
from its last “ Council’s Report,” p. 19, will suffice as a 
sample of the mischief :— With a view to promote the 
study of Entomology and Botany among the members of 
the Society and their families, the Council, in the early 
part of the year, announced their intention of giving two 
prizes of 5, 5s. each, one for the best Botanical collection, 
the other for the best collection of Lepidopterous Insects ; 
all specimens to be gathered or taken within the West 
Kent district.” This quotation is by no means intended 
for blame to any particular society, but merely as an 
example taken from one of the printed “ Reports” that has 
lately reached me of what is still being sown broadcast 
generally throughout the country. 
And here we have plainly not only a reward of money 
for the best collection of plants and Lepidoptera in a given 
district, but a temptation or inducement to unscrupulous 
collectors, in their anxiety to win the prize and defeat 
their competitors, to destroy such rare specimens as they 
may not take away. Such nefarious conduct is not meant 
to be insinuated of the West Kent Society ; but my ob- 
ject is simply to assert that which I know has too often 
been the effect of such prizes, and to invoke the aid of 
NATURE in suppressing the evil, 
- GEORGE GULLIVER 
A FRENCH PAYSICAL SOCIETY 
HE scientific movement increases in France; it 
began about the end of the Empire, under the 
ministry of Duriiy, and has since taken greater propor- 
tions, especially after the last war. The new French 
Association for the Advancement of Science,* it is well 
known, is modelled after the British Association, the suc- 
cess of which has surpassed expectation. 
The physicists of Paris have assembled for several years 
in the laboratories of the Superior Normal School, placed 
at their disposal by M. Berlin, the director of the scientific 
studies of this school. They conversed about physics, 
* See NaATuRE, vol. v. p. 357- 
