QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 307 



first, and the coat next in order — both, however, being pro- 

 duced by differentiation from the same mass of parenchyma." 

 It is difficult to accept this view — unsupported as it is by- 

 similar facts — without further investigation. 



9. Ovule and Seed. — i. In an elaborate paper ('Ann. des 

 Sc. Nat./ 5 ser., xix, 5) on the development of these structures 

 in SchropJiulariaceoe, Solunacea, Boraginacece, and Labiatce, 

 Chatiu appears to have arrived at no general result of import- 

 ance. He congratulates Ijimself on having seen a pollen tube 

 enter the micropyle of Veronica Chamcedrys. Schacht long 

 ago pointed out that this phenomenon might generally be 

 demonstrated in V, serpyUifolia, when the corolla had just 

 fallen. 



ii. Dr. Hooker, in a paper in the ' Journ. Linn. Soc.,' xiv, 

 182-188, identifies the Hydnora americana of E. Brown 

 with De Bary's Prosopanche. He confirms Ue Bary's 

 observation of the ovules being actually buried in and con- 

 fluent with the placental tissues. 



iii. According to Warming (1. c, xvi and xxxv) ovules 

 are most frequently metamorphosed caulomes. They origi- 

 nate beneath the first layer [Euphorbia, Scrophularia) of the 

 periblem, sometimes in this layer itself [Ranunculus acris), 

 or as buds on tlie base of foliar organs [Salix). The in- 

 teguments of Euphorbia originate in a great measure in the 

 dermatogen. Warming regards these as phyllomes and the 

 nucleus as a caulome. The embryo-sac is sometimes formed 

 of a cell of the first layer of periblem [Scrophularia.) In 

 Euphorbia it appears to originate from the second layer. 



