XXVlll Obituary Notices of Fellows deceased. 
years were always a great pleasure to him. Lent and May terms, 1888, were 
spent as usual in Cambridge, but June to December were given up to 
Plymouth, with a brief Christmas holiday in Munich. And here we must 
note the beginning of a new phase in Weldon’s ideas. His thoughts were 
distinctly turning from morphology to problems in variation and correlation. 
He has left on record the nature of the problems he was proposing to himself 
at this time, and they are summed up as follows :— 
(1) The establishment of a new set of adult characters leading to the 
evolution of a new family has always been accompanied by the evolution of 
a new set of larval characters leading to the formation of a larval type 
peculiar to the newly established family ; the two sets of characters having 
as yet no demonstrable connection one with the other. 
(2) The evolution of the adult and that of the larval characters peculiar 
to a group advance pari passu one with the other, so that a given degree 
of a specialisation of adult characters on the parts of a given species implies 
the possession of a larva having a corresponding degree of specialisation and 
vice Versa. 
The next year was to place in Weldon’s hands a book—Francis Galton’s 
“Natural Inheritance,” by which one avenue to the solution of such problems, 
one quantitative method of attacking organic correlation, was opened out. 
From this book as their source sprang two notable friendships and the 
whole of the biometric movement, which so changed the course of his life and 
work. In 1889, also, another change came. Weldon found that his dredging 
and collecting work separated him from his books for half his time. 
Accordingly, he applied for a year’s leave from Cambridge, and he and his 
wife settled down in a house of their own at Plymouth. This period of 
hard work lasted through 1890, and was broken only by flying visits to 
Dresden in September and at Christmas, 1889, and an autumn visit in 1890 
to Chartres and Bourges. The intellectual development and the experience 
and knowledge gained in this period were far more important than the mere 
published work would indicate. In 1889, Weldon investigated the nature of 
the curious enlargement of the bladder associated with the green, or excretory, 
glands in certain Decapod Crustacea, and published in October of the same 
year his paper of “The Coelom and Nephridia of Palemon servatus.” The 
result of his investigation was to confirm “the comparison so often made 
(by Claus, Grobben, and others) between the glomerulus of the vertebrate 
kidney and the end-sac of the Crustacean green gland.” A little later, June, 
1891, he published the results of more extended researches in this field in 
what proved to be his last strictly morphological paper. It was entitled: 
“The Renal Organs of certain Decapod Crustacea.” In this he showed that 
in many Decapods spacious nephro-peritoneal sacs “should be regarded 
rather as enlarged portions of the tubular system ... than as persistent 
remnants of a ‘ccelomic’ body cavity, into which the tubular nephridia 
open.” 
One further paper of a year later may be best referred to here, Weldon’s 
