All I can think of without seeing a picture is what's called, pardon me, Dog Barf fungus.

It appears after lots of rain, grows on mulch as the link says and is actually a slime mold, well, I'll let you read the link below and look at the pictures.

Carolyn

Here is a link that might be useful: Dog stuff

Well, we really need a picture....I think you know that. :-)

But, if I were to guess, I'd say that you're seeing what is commonly called slime mold. It's NOT a mold nor a fungus but a simple protist, often unicellular with many nuclei. There are many many different kinds of 'slime molds', but they pose no problem for your tomato plant.

A quick Google search about slime mold and their images should shed some light on your mystery.

I would just blast them off with water hose.

Doesn;t work Seysonn. If you look at the link I posted you;ll see where it says how sticky they are when adhering to a surface.,

And yes, I've had a bit of experience with slime molds, remember, retired Microbiologist here, and water is not going to work IMO,.

Carolyn

If it's slime mold, can just ignore it because it's not damaging the plants..
It will go away on its own accord.

Carolyn,

We are thinking of two different things : OP wrote:

>>>> the masses consist of thousands of tiny (what looks like insect eggs or mold colonies).Note the description : """ of thousands of tiny ... insect eggs"""slimy inside"""

So based on that description I was thinking of something like this :

As a follow up, yes Carolyn, it looks like you nailed it with the "dog barf" fungus. Thank you all very much for the info. In this case, I am glad to know it is nothing to worry about.

Happy growing all!