458 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of the Phylactolnsmata. The study was favoured by the transparency of 
the gelatinous ectocyst, the unique size of the polypide, and the prompt- 
ness with which it is evaginated. The largest colony seen measured 
7 cm. in diameter. The author proposes to apply the term polyzooid 
to every equal part of a colony which consists of a polypide and 
a portion of the ccenoecium, and to call “ cystid ” such portion of the 
coenoecium. 
In his detailed account of the organization of his new species the 
author does not confine himself to new facts. He confirms the state- 
ment of Verworn as to the presence of cilia at the end of the external 
wall of the stomach. He denies the existence of a circumoesophageal 
commissure ; the ovary is a solid club-shaped outgrowth of the internal 
lining epithelium. He found muscular fibres in the funiculus, though 
their presence in Cristatella has been denied by Yerworn. The stato- 
blast and its development are described in considerable detail. 
Arthropoda. 
Extremities of Embryo of Arachnids and Insects.* — Dr. A. 
Jaworowski has been led to construct the following table : — 
Arachnida. Insecta. 
fist appendage, 
Antennae iu em- 
Antennae also in post-embryonic^ 
bryo only. 
stage. 
2nd „ 
Mandibles. 
Mandibles. 
3rd „ 
Maxilla; i. 
Maxillae i. 
4th „ 
Maxillae ii, later 
Maxillae ii., fused in embryo and 1 
1st pair of legs. 
forming labium. J 
5th „ 
Later 2nd pair of 
legs. 
1st thoracic appendage. v 
6th „ 
Later 3rd pair of 
legs. 
2nd „ „ 1 
7th „ 
Later 4th pair of 
3rd „ „ | 
legs. 
J 
[ 12 (?) abdominal 
segments in Tro- 
11 embryonic abdominal segments.^ 
1 chosci singoriensis. 
\ 4-5 pair of abdominal appendages 
Abdominal appendages of varying f 
1 in general. 
number. J 
a. Insecta. 
Chemistry of Insect Colours.f — Mr. F. H. Perry Coste has investi- 
gated the behaviour of the colours of Lepidoptera when treated with 
various chemical reagents. He gums the wings on to watch-glasses and 
then submits them to the action of reagents for one hour. 
After describing his a priori expectations, and pointing out that 
in nearly every instance he has succeeded in modifying the colours 
retrogressively only, and not progressively , he describes his method of 
working and the reagents used. After experimenting with about two 
dozen different reagents, he concluded to make use of hydrochloric, nitric, 
sulphuric, and acetic acids ; of potassic, sodic, and ammonic hydrates. 
He finds no difference between the action of acids and of alkalies, except 
that some colours are affected more by the one, some by the other ; but 
* Zocl. Anzeig., iv. (1891) pp. 164-9, 173-6 
t Entomologist, April 1890-August 1891. 
