9 4 
THE JOURNAL OF BOTANY 
Some hundred living species have been described, hut only six or 
seven are common in the planktons. The parent cells, each consist¬ 
ing of two valves with a hoop between them, form colonies, holding 
together by means of long seta?; the structure of the colony endows 
it with great floating capacity. Two features of the genus are espe¬ 
cially puzzling : one is that several of the species, though not all, have 
the capacity to develop inside the mother-cells peculiar internal 
organs, covered with a thick siliceous wall; these organs are called 
stcitospores. No one has ever seen them germinate, and whether they 
are organs of reproduction, or something like endocysts, or something 
else, is not known. The other strange feature is, that although it is 
so infinitely numerous in the planktons, the mother-cells, or colonies, 
as such, never appear in any fossil marine deposits. On the other 
hand, the spores do appear fairly often as fossil remains: fossil spores 
of Chcetoceros are to be found frequently enough in miocene diato- 
maceous earths; the most common form is Syndendrium Ehr., which 
is the spore of C. dicidema Gran, very common in the planktons. 
Why it is that the vegetative form cannot stand fossilization whilst 
the spore can do so, is not known. 
In the Lancashire and Cheshire Naturalist for December- 
January, Mr. W. H. Pearson gives an interesting account of his 
visits to Dolgelley, the first of which occurred fifty years ago, the last, 
in company with a party of bryologists, in August last. In the course 
of his paper Mr. Pearson has the following paragraph relating to 
Carrington and their fasciculi of Hepaticce, which we think may 
interest some of our readers :—“ About this time [1874] the Eccles 
Co-operative Society inaugurated a scheme for the education of the 
masses, and Dr. Carrington became the teacher of a class on Botany, 
which [W. H.] Stansfield and I joined. Although such a distin¬ 
guished cryptogamic botanist, he was of a shy, retiring nature, with 
little ability to teach general Botany, and in the course of a few 
weeks the class, which began with a membership of 40 to 50, dwindled 
down to two, Stansfield and myself. Then Stansfield ceased to come. 
Dr. Carrington, I think admiring my perseverance, invited me to his 
house, and I began to take an interest in Hepaticae. He then 
suggested that I should help him in issuing a Fasciculus of Hepaticae, 
and as time and labour were of little moment then, we brought out 
Carrington and Pearson’s ‘ Hepaticae Britannicae Exsiccatae,’ when I 
call to mind that we issued 60 copies of each Fasciculus, and each 
Fasciculus contained 75 specimens, four fasciculi were published, and 
18,000 specimens packeted and labelled. We presented half the 
copies to friends who had contributed specimens, and to other hepati- 
cologists, and the cost of binding and printing left a few pounds to 
divide between us, as I find in looking over some old memoranda. 
The Fasciculi have no doubt been of service to students, but there are 
numerous mistakes, which I suppose some authority will take the 
trouble to point out some time or other.” 
At the meeting of the British Mycological Society held on 
January 20 at University College, the papers were: Dr. H. Wor- 
mald, “ Crown Gall in Nursery Stock,” which dealt with the tumours 
of the crown gall type found on numbers of cultivated plants in this 
